High-Pressure Ultrafast Time-Resolved Far-Infrared Full-spectrum Spectroscopy with Air-Based Upconversion

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The ultrafast dynamics of these excitations significantly influence the fundamental physical and chemical properties of the materials. Moreover, modulating the dynamics of these excitations through pressure variations is intriguing for unveiling the key microphysical processes involved and can offer dynamic experimental support for exploring novel materials. In this study, we demonstrate the first experimental elucidation and application of ultrafast time-resolved far-infrared full-spectrum spectroscopy combined with high-pressure diamond anvil cell (DAC) technology. The combination of an air-plasmon-based continuum and an air-based single-shot upconversion detection technique have been first employed in high-pressure time-resolved infrared spectroscopy. The air-plasmon-based ultrabroadband far-infrared continuum was directed into a DAC and the transmitted pulse was detected in a single shot form through four-wave mixing in the air to avoid the absorptions from phonon modes of the nonlinear medium. It allows the real-time capture of the spectrum spanning from 1800 cm − 1 , with a few-cm − 1 spectral resolution. We investigate the pressure-dependent vibrational coupling dynamics of the complete set of vibrational fingerprint modes in microcrystalline octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) following mode-selective vibrational mode excitation. The results reveal that pressure enhances the vibrational coupling and energy transfer between the excited vibrational modes and doorway modes. The combination of high-pressure technology and time-resolved full-spectrum infrared spectroscopy opens up new perspectives for the study of the ultrafast phenomena in material science. Physical sciences/Optics and photonics/Optical techniques/Optical spectroscopy/Infrared spectroscopy Physical sciences/Optics and photonics/Optical physics/Supercontinuum generation Figures Figure 1 Figure 2 Figure 3 Figure 4 Full Text High-pressure time-resolved spectroscopy has gained widespread applications in various fields, including materials science, chemistry, and geophysics 1–8 . It is an essential tool for studying dynamic processes occurring in materials under high-pressure conditions, such as those encountered deep within the Earth’s interior or during shock compression experiments. Particularly, high-pressure time-resolved infrared spectroscopy is a powerful method for investigating the kinetics and mechanisms of chemical reactions, phase transitions, and structural transformations under extreme pressure 9 . Its capability to capture ultrafast molecular dynamics provides valuable insights into energy flow, structural changes, and intermolecular interactions. Despite its significance, there have been only a few prior studies of time-resolved infrared spectroscopy under high pressure. In 2009, nanosecond time-resolved transient infrared spectroscopy in the mid-infrared region was used to investigate the photolysis of TATB under high pressure 9 . In 2014, sub-picosecond time-resolved two-dimensional infrared spectroscopy in the spectral range of 2200-2700 cm -1 with hole-burning methods was employed to study water dynamics under high pressure 10 . In 2018, sub-picosecond time-resolved optical pump infrared probe measurement was conducted to study the phase transition of VO 2 probed with 10-μm infrared pulses under high pressure 11 . In 2021, sub-picosecond time-resolved THz spectroscopy was used to study the dynamics of photo-induced carriers in GaAs under high pressure 12 . However, these infrared experiments were constrained by the narrow bandwidth of the infrared pulses used, allowing only single bands of vibrations to be probed. This limitation precluded a global view of dynamics. Furthermore, due to a shortage of sensitive detectors currently available, there are constraints in conducting time-resolved spectral measurements in the far-infrared spectral region (~50–600 cm⁻¹, ~1.5–18 THz) 13 . This spectral region holds unique importance in the fields of the material science of physics 14 , chemistry 15 and biology 16 , given the presence of various excitations such as molecular vibrations, molecular rotations, phonons, carriers, Cooper pairs, excitons, spin-orbit coupling resonating within this energy range 17 . For instance, lattice modes and doorway modes of energetic molecular crystals play crucial roles in the shock detonation initiation of explosives, located in the 0-200 cm -1 and 200-800 cm -1 range, respectively 18,19 . Changes in the population distribution of these modes during shock-induced detonation are expected to lead to time-dependent changes in the far-infrared vibrational spectrum. While conventional two-dimensional time-resolved terahertz spectroscopy (2D TRTS) can be employed for acquiring time-resolved spectra in far-infrared 14 , it is time-consuming, necessitating the collection of hundreds of data points along the THz detection delay for each pump-probe delay 20–22 . Additionally, due to the absorption from phonon modes of electrooptic crystals, real-time detection of the full-spectrum far-infrared spectrum poses a challenge in single-shot terahertz time-domain spectroscopy (THz TDS) using electro-optics sampling (EOS) detection, with most of work being done between 0.5 and 3 THz (between 20 and 100 cm -1 ) 14 . In this paper, we present the first high-pressure ultrafast time-resolved full-spectrum far-infrared spectroscopy spanning from 1800 cm -1 . The generation of the air-plasmon-based infrared continuum is effectively achieved by utilizing two-color laser filaments with a commercial femtosecond laser. This ultrabroadband continuum serves as the probe light source, providing sub-cycle coherent infrared pulses that benefit time-resolved pump-probe measurements 23 . In contrast to previous works, where the mid-infrared continua were obtained 24–27 , the spectrum of the infrared continuum in this work is extended to the far-infrared using 100-fs laser pulses. A single-shot nonlinear upconversion detection scheme 28 is employed to detect the entire spectrum of the infrared continuum in real-time. To avoid light absorption by the nonlinear crystal, air is selected as the nonlinear medium. Given the isotropy of air, the third-order nonlinear optical process is applied in this method 29 . This process results in the upconversion of infrared light to visible light, capturing the complete spectrum of the infrared continuum by simply shifting the spectrum of the upconverted visible light, recorded using a high-performance visible dispersive spectrometer. Consequently, nonlinear spectral upconversion is achieved in a single shot, allowing direct detection across the entire source spectral range in the frequency domain without the need for Fourier transformation as required in conventional THz TDS. Compared to commercial FTIR spectrometers and infrared dispersive spectrometers with an MCT array detector, this method not only enables simultaneous detection of both mid-infrared and far-infrared without the need for additional mid- and far-infrared detectors, but also allows for measurement of the entire infrared spectrum in a single shot. To showcase the advantages of this system, we present the full transient far-infrared absorption spectrum of the complete set of vibrational fingerprint modes in the energetic molecular microcrystal of HMX, a typical energetic molecular material, following excitation of the stretching vibration of nitro groups under the conditions of greatest interest: the regime of relatively weak shock waves (pressure, p = 1-10 GPa) characteristic of accidents 30 . The schematic of the experimental setup is shown in Fig. 1. A commercial Ti:sapphire amplifier (800nm, 1kHz) is employed to provide 100-fs pulses with an energy of 6mJ, which is subsequently split to three beams with an energy ratio of 1:1:4. The first beam is used to induce the infrared continuum generation by driving the air plasmon. The nonlinear crystal BBO is used for second harmonic generation (SHG) of the fundamental laser, achieving a 5% conversion efficiency. A collinear configuration, where the fundamental and SHG beams are not separated, is used to stabilize the output intensity. The time dispersion of the fundamental and SHG pulses is compensated by carefully rotating a phase retarder. A 3-mm length plasma is generated by focusing the pulses of the fundamental and SHG laser in air. A conical infrared continuum emission is produced through the light-matter interaction of the two-color laser field and air plasma 31 . A pulse energy of 50 nJ is measured using a pyroelectric joulemeter (J-10mb-e, Coherent) behind a silicon window, which filters the continuum from the residual light. The silicon window reflects half of the energy, indicating that the total energy of the produced infrared continuum is approximately 100 nJ. The continuum is focused onto a DAC with a culet size of 600μm by a parabolic mirror, with a focal spot size of 300 μm. The continuum passing through the DAC is then collimated by a parabolic mirror, and its spectrum is detected by the second beam. The second beam, used as detection light, is initially stretched to generate chirped pulses with a time duration of 10ps using a grating stretcher, ensuring high detection spectral resolution. Subsequently, it is focused, by a lens to the air in the detection cell through the 3-mm hole in the center of a parabolic mirror. The infrared continuum is focused to overlap the focal spot of the chirped beam by the parabolic mirror. The field of the infrared continuum induces a four-wave different frequency (FWDFG) process, generating a visible mixture light with a pulse energy of several picojoules. The frequency of the mixture light is expressed as \({\omega }_{vis}=2{\omega }_{nir}-{\omega }_{con}\) , with ω nir and ω con denoting frequencies of the chirped light and the infrared continuum, respectively. The spectrum of the visible mixture light is recorded using an optical spectrometer and a commercial EMCCD detector after filtering out the residual chirped light with a broadband short-pass filter. Then, the entire spectrum of the infrared continuum can be obtained by simply shifting the spectrum of the visible light. The delay line τ 1 is used to find out the temporal overlap of the chirped pulses and continuum pulses, and it doesn’t need to scan during detection, which means that the spectrum of the infrared continuum can be obtained by a single pulse. According to the four-wave mixing generation theory 29 , the derived FWDFG efficiency F 2 is governed by an integration given as $$\begin{array}{c}{F}_{2}={\left|{\int }_{-l}^{l}dx\frac{\text{exp}\left(-i\varDelta kx\right)}{1+{\left(2x/k{}_{0}^{2}\right)}^{2}}\right|}^{2} \left(1\right)\end{array}$$ where 2 l is the length of the FWDFG region, k and ζ 0 is the wave vector and beam-waist radius of the generated beam, respectively, and Δ k ~ 0 is the wave-vector mismatch in air. In accordance with Eq. (1), it is evident that efficiency is only dependent upon geometric parameters and remains independent on the frequency and intensity of infrared light. This characteristic implies the potential of FWDFG for detecting transient changes in infrared light intensity for the entire infrared range. It is noticed that, given the utilization of chirped pulses for upconverting the infrared, consideration must be given to the cross-phase distortions within the spectrum of the visible mixture light. These cross-phase modulations are addressed using algorithms as detailed in literatures 32 – 34 . Briefly, the compensation involves adjusting the phase of the Fourier transform of the measured spectrum through the time-dependent phase of the chirped pulse 33 given as $$\begin{array}{c}\left(t\right)=\frac{{\omega }^{\left(1\right)}{t}^{2}}{2} \left(2\right)\end{array}$$ where, the chirped rate parameter ω (1) is 4 rad/ps 2 in this work, corresponding to a second-order spectral-phase parameter of 0.25 ps 2 . The third beam with a pulse energy of 4mJ is used to pump an optical parameter amplifier, the outputs of which are used to generate excitation pulses. The excitation pulses are used to excite the sample in transient spectrum measurement. The pump beam is focused to the DAC by a lens through the 3-mm hole in the center of PM2. The focal spot size of the pump beam is 500µm, slightly larger than that of the infrared continuum. The Delay line is used to vary the time delay between the excitation and probe pulses. The optical path for infrared pulse is purged with dry air or nitrogen gas, shown as the light grey area in Fig. 1. First, the spectrum of the continuum light source was measured. The spectra of the infrared continuum through no sample cell and through a DAC are shown in Fig. 2(a). Here, an enhancement in the far-infrared region of the spectrum extends the infrared continuum, spanning six octaves and covering nearly the entire mid- and far- infrared range ( 2400 cm − 1 or 72 THz). Compared with the previous work 25 , the whole spectrum in this work is red-shifted, achieved by employing a laser pulse with a longer duration because the center frequency of the infrared continuum is determined by the duration of laser pulses. According to the infrared continuum theory 35 , the contribution of the four-wave mixing process dominates the generation of the infrared continuum in the long-filament regime. Therefore, the electric field can be expressed as $$\begin{array}{c}{E}_{ir}\left(\omega \right)\propto {\omega }^{2}F(E\left(t{)}^{3}\right) (3)\end{array}$$ where F ( E (t) 3 ) is the Fourier transform of E (t) 3 , E ( t ) denotes the electric field with the fundamental and its SHG 36 . Given that: $$\begin{array}{c}E\left(t\right)={E}_{0}\left(\sqrt{1-r}\text{exp}\left(-\frac{{t}^{2}}{{{t}_{p}}^{2}}\right)\text{cos}\left({\omega }_{0}t\right)+\sqrt{r}\text{exp}\left(-\frac{2{t}^{2}}{{{t}_{p}}^{2}}\right)\text{cos}\left(2{\omega }_{0}t\right)\right) \left(4\right)\end{array}$$ where t p , r and ω 0 denote the pulse duration parameter, the SHG intensity fraction, and the fundamental central frequency. Thus, E ir (ω)∝ω 2 exp(-ω 2 /(4/ t p ) 2 ), and we expect a maximum at ω = 4/ t p , which is inversely proportional to the pulse duration. A longer pulse duration results in a higher contribution of low-frequency component, consistent with previous simulation work 37 . For 100-fs pulses with t p =85 fs, the central frequency is around 250 cm − 1 , which agrees well with the experimental result. The broadening of the high-frequency component of the continuum is likely a result of the spectral self-broadening of the fundamental pulses. The low-frequency part of the continuum spectrum with a sub-mm-scale spot size is attenuated slightly by the DAC with a small clear aperture, while the high-frequency part is absorbed by the DAC due to the intrinsic absorption band of the diamond in the 2000 cm − 1 region, leading to narrowing of the measurable spectral range: from 1800 cm − 1 . The spectrum exhibits a smooth overall profile, indicating that this source is well-suited for use as probe light. The fine structures due to the absorption of silicon window at ~ 610 cm − 1 and silica protective overcoat on mirrors at ~ 1250 cm − 138 are evidently observed. The absorption lines of water vapor in the 200 cm − 1 and 1600 cm − 1 regions have also been clearly observed in Fig. 2(b) and Fig. 2(c), in good agreement with the water vapor absorption spectrum from the HITRAN database 39 broadened by a Gaussian function with a 4-cm − 1 bandwidth, which indicates that the spectral resolution of this system is around 4 cm − 1 . To accurately determine the zero delay time and instrumental response function (IRF) of this system, cross-correlation measurements using a undoped germanium (Ge) wafer was performed at ambient pressure in the DAC, as previously employed in mid-infrared range 2640 . The multi-photon absorption of mid-infrared excitation pulses generates the photo-induced carriers in the Ge wafer, leading to a transient absorption in the far-infrared region, as shown in Fig. 3(a). The recombination relaxation lifetime of photo-induced carriers is on the 1 ns time scale, in agreement with the experimental result ever reported 41 . The broadband transient spectrum around t = 0 contributes to the Kerr effect, a nonlinear process caused by changes in refractive index due to the pump pulse propagation. The cross-correlation trace S for the Kerr effect can be fitted by convoluting a Gaussian function with a bi-exponential decay, given by $$S=\text{exp}\left(-\frac{{\left(t-{t}_{0}\right)}^{2}}{2 {d}^{2}}\right)\otimes h\left(t-{t}_{0}\right)\left({a}_{1}\text{exp}\left(-\frac{t-{t}_{0}}{{t}_{1}}\right)+{a}_{2}\text{exp}\left(-\frac{t-{t}_{0}}{{t}_{2}}\right)+{a}_{3}\right)$$ $$={a}_{1}\left(1+\text{erf}\left(\frac{t-\left({t}_{0}+\frac{{d}^{2}}{{t}_{1}}\right)}{\sqrt{2}d}\right)\right)\text{exp}\left(-\frac{t-\left({t}_{0}+\frac{{d}^{2}}{2{t}_{1}}\right)}{{t}_{1}}\right)$$ $$+{a}_{2}\left(1+\text{erf}\left(\frac{t-\left({t}_{0}+\frac{{d}^{2}}{{t}_{2}}\right)}{\sqrt{2}d}\right)\right)\text{exp}\left(-\frac{t-\left({t}_{0}+\frac{{d}^{2}}{2{t}_{2}}\right)}{{t}_{2}}\right)$$ $$\begin{array}{c}+{a}_{3}\left(1+\text{erf}\left(\frac{t-{t}_{0}}{\sqrt{2}d}\right)\right) \left(5\right)\end{array}$$ where t 0 denotes the zero delay time, d = IRF/2, h(t) is the Heaviside unit step function, and a 1 , a 2 , a 3 and t 1 , t 2 are pre-exponential factors and time constants of the exponential function. Figure 3(b) shows a representative cross-correlation trace at 700 cm − 1 . As seen in Fig. 3(c), the change of t 0 with frequency indicates that the relative chirp of the infrared continuum is less than 90 fs across the entire spectral range. This small chirp is attributed to the low dispersion of diamond. Figure 3(d) shows that IRF of each frequency component remains around 0.3 ps for all frequencies, mainly determined by the time duration of the pump pulse. Additionally, the signal observed in Fig. 3(a) at approximately 1280 cm − 1 is a coherent artificial signal resulting from the up-conversion signal of the scattered pump light. Although the Ge system can serve as a good benchmark for our new technique, the carrier relaxation exhibits similar behavior at different frequencies and can be detected by conventional narrow-band infrared pump-probe spectroscopy using optical parametric amplifiers. To illustrate the capability of full-spectrum infrared spectroscopy, we conducted transient vibrational spectrum measurements of the complete set of vibrational fingerprint modes to study vibrational coupling dynamics in microcrystalline HMX under different pressures in DAC. In this case, both a broad spectral range and high spectral resolution are necessary for effectively detecting and analyzing the overall dynamics of the distinguishable vibrational modes under high pressure. The center frequency of the excitation pulses is tuned to 1280 cm − 1 to resonate with the nitro group symmetric stretching vibration of the HMX crystal. The pressure-dependent transient spectra covering the entire fingerprint region of HMX at 400ps delay time under four pressures in the 200−1700 cm − 1 range following excitation of the stretching vibration of nitro groups are presented in Fig. 4(a). A negative transient absorption value is assigned to bleach features (resulting from stimulated emission or loss of ground state absorption), while a positive value is assigned to excited state absorption features. The transient absorbance peaks evidently exhibit a blue shift and decrease as the pressure increases, as shown in Fig. 4(a), as their steady-state absorbance peaks broaden, weaken and blue-shift with increasing pressure 42 . Attaining this broadband far-infrared time-resolved spectrum would be challenging and time-consuming by conventional 2D TRTS or infrared dispersive spectrometer, while here we implement the real-time full-spectrum far-infrared (or THz) transient spectrum measurement using single-shot detection by air-based upconversion method. As regards the time evolution of these fingerprint modes, Figs. 4(b-e) display the dynamics traces of the representative doorway mode near 600 cm − 1 , one of the three near-degenerate in-plane bending vibrations in the 600 to 700 cm − 1 range. These traces are fitted with a mono-exponential curve. The rising signals represent the vibrational energy transfer from the nitro stretching to the bending vibration. This process emerges after t = 0 and continues until thermal equilibrium is reached. Figure 4(f) indicates that the time constant, ~ 100 ps at ambient pressure, decreases with pressure and is reduced by a factor of 10 under 7.3 GPa. This observation reveals that the coupling is enhanced under compression, consistent with the early theory proposed by Fayer and Dlott 30 , which stated that the principal effect of pressure on the transfer rate was the increase in the anharmonic coupling. It is suggested that the pressure-enhanced coupling between vibrational modes and doorway modes determines the sensibility of energetics under relatively weak shock waves (pressure p = 1−10GPa). In conclusion, we have introduced a novel high-pressure, real-time ultrafast time-resolved infrared spectroscopy capable of spanning multiple octaves (from 1800 cm − 1 ) and covering the entire far-infrared range. The far-infrared continuum is generated through two-color laser filaments using 100-fs pulses and is detected using single-shot detection with air-based up-conversion. Transient spectra in the 30–2400 cm − 1 range can be acquired with a resolution of a few cm − 1 . The six-octave spanning spectrum covers the entire molecular fingerprint region (50–1500 cm − 1 ) and a significant portion of the functional group region (1500–4000 cm − 1 ). With a full-spectrum infrared source, this detection method can essentially cover the entire infrared range. Combining this spectroscopy with high-pressure DAC technology, we investigate the vibrational coupling of all fingerprint modes in microcrystalline HMX following infrared excitation under various pressures, revealing pressure-dependent coupling enhancement between the excited modes and doorway modes. This observation highlights the effectiveness of our method in capturing comprehensive vibrational changes within energetic molecular systems. Furthermore, the ability to probe the entire infrared spectrum under high pressure in a single laser shot will facilitate the study of a broader range of phenomena beyond vibrational coupling in energetic materials. For example, it can be used to investigate energy transfer between high- and low-frequency vibrational modes in other molecular systems such as the vibrational coupling between the bending and liberating modes in water 43 – 45 or the lattice modes of high-pressure phases of ice 46 . It can also be applied to study carrier or exciton relaxation with broad spectral changes and their coupling with phonons in quantum dots 4 , 47 , 2D materials 48 and bulk semiconductors 1 , 2 . We believe that this novel spectroscopy approach holds great potential for future research. Methods Sample preparation The HMX sample powder was placed on one of the diamond flats and then gently pressed to the desired thickness (generally a few µm because of the strong mid infrared absorption). For pressure-loading measurements, stainless steel gaskets with an initial thickness of 200µm were indented to about 60µm, a hole with an initial diameter of 300µm was drilled in the center of the indentation, and a micro ruby ball was placed on the edge of the pressure chamber as pressure sensors as shown in Fig. 1 . The preindented thickness was chosen to be much larger than the sample thickness to prevent the diamonds from damaging each other under load. The remainder of the gasket hole was filled with the pressure-transmitting medium KBr. Time-resolved absorption spectrum measurement In time-resolved absorption spectrum measurements, a pulse-to-pulse scheme was used, wherein a mechanics chopper operated at 500 Hz to modulate the excitation beam. The transient signal is expressed as the spectral absorbance change S(ω) = log(Σ I 2i /Σ I 2i + 1 ), where I 2i and I 2i + 1 represent the spectral intensity of the even and odd probe pulses, respectively. Meanwhile, I 2i and I 2i + 1 represent the situations without and with excitation, respectively. Declarations CONFLICT OF INTEREST The authors declare no conflict of interest. AUTHOR CONTRIBUTIONS The main setup was designed and built by GZ and YZ. The measurements were taken by GZ, YZ and JM. The DAC samples were prepared by YZ and GY. The data acquisition and analysis programs were written by GZ. ZZ offered assistance in theoretical analysis of experiment data. GZ and YY coordinated the project and wrote the manuscript. All authors participated in the discussion of results and reviewed the final manuscript. ACKNOWLEDGEMENTS This research was financially supported by the National Natural Science Foundation of China (Grant No. U2030113) and by the National Key Laboratory of Shockwave and Detonation Physics (Grant No. 2021JCJQLB05712). DATA AVAILABILITY The data that support the findings of this study are available from the corresponding author on reasonable request. References Cheng P, Wang Y, Ye T, Chu L, Yang J, Zeng H et al. Semiconductor-metal transition in lead iodide under pressure. Appl Phys Lett 2022; 120: 212104. Du L, Shi X, Duan M, Shi Y. Pressure-Induced Tunable Charge Carrier Dynamics in Mn-Doped CsPbBr3 Perovskite. Materials (Basel) 2022; 15: 6984. Wu YL, Yin X, Hasaien JZL, Tian ZY, Ding Y, Zhao J. On-site in situ high-pressure ultrafast pump-probe spectroscopy instrument. Rev Sci Instrum 2021; 92: 113002. Cheng JC, Pan LY, Huang XL, Huang YP, Wang YH, Xu SP et al. Interparticle spacing effect among quantum dots with high-pressure regulation. Nanomaterials 2021; 11: 1–9. Tsuchiya S, Nakagawa K, Yamada J, Toda Y. Carrier Relaxation Dynamics in the Organic Superconductor κ-(BEDT-TTF)2Cu(NCS)2 Under Pressure. J Supercond Nov Magn 2016; 29: 3071–3074. Hébert P, Saint-Amans C. Study of the laser-induced decomposition of energetic materials at static high-pressure by time-resolved absorption spectroscopy. J Phys Conf Ser 2014; 500: 022002. Liu B, He C, Jin M, Wang Q, Lin SH, Ding D. High pressure effect on the ultrafast energy relaxation rate of LDS698 (C19H23N2O4Cl) in a solution. OE 2010; 18: 6863–70. Gump J, Parker L, Peiris SM, Gump J, Parker L, Peiris SM. HMX (Beta Phase): Laser-Ignited Reaction Kinetics and Isothermal Equations of State. Shock compression Condens matter 2003; 706: 967–972. Glascoe EA, Zaug JM, Armstrong MR, Crowhurst JC, Grant CD, Fried LE. Nanosecond time-resolved and steady-state infrared studies of photoinduced decomposition of TATB at ambient and elevated pressure. J Phys Chem A 2009; 113: 5881–5887. Fanetti S, Lapini A, Pagliai M, Citroni M, Di Donato M, Scandolo S et al. Structure and dynamics of low-density and high-density liquid water at high pressure. J Phys Chem Lett 2014; 5: 235–240. Braun JM, Schneider H, Helm M, Mirek R, Boatner LA, Marvel RE et al. Ultrafast response of photoexcited carriers in VO2 at high-pressure. New J Phys 2018; 20: 083003. Xu S, Huang D, Liu Z, Zhang K, Jiang H, Gou H et al. Hydrostatic pressure effect of photocarrier dynamics in GaAs probed by time-resolved terahertz spectroscopy. OE 2021; 29: 14058–14068. Friš P, Dubroka A. Vacuum variable-angle far-infrared ellipsometer. Appl Surf Sci 2017; 421: 430–434. Schmuttenmaer CA. Exploring dynamics in the far-infrared with terahertz spectroscopy. Chem Rev 2004; 104: 1759–1779. Haran G, Sun WD, Wynne K, Hochstrasser RM. Femtosecond far-infrared pump-probe spectroscopy: A new tool for studying low-frequency vibrational dynamics in molecular condensed phases. Chem Phys Lett 1997; 274: 365–371. Vatansever F, Hamblin MR. Far infrared radiation (FIR): Its biological effects and medical applications. Photonics Lasers Med 2012; 1: 255–266. Basov DN, Averitt RD, Marel D van der, Dressel M, Haule K. Electrodynamics of correlated electron materials. Rev Mod Phys 2011; 83: 471. Bernstein J. Ab initio study of energy transfer rates and impact sensitivities of crystalline explosives. J Chem Phys 2018; 148: 084502. Ye S, Koshi M. Theoretical Studies of Energy Transfer Rates of Secondary Explosives. J Phys Chem B 2006; 110: 18515–18520. Valdés Aguilar R, Qi J, Brahlek M, Bansal N, Azad A, Bowlan J et al. Time-resolved terahertz dynamics in thin films of the topological insulator Bi2Se3. Appl Phys Lett 2015; 106: 011901. Yettapu GR, Talukdar D, Sarkar S, Swarnkar A, Nag A, Ghosh P et al. Terahertz Conductivity within Colloidal CsPbBr3 Perovskite Nanocrystals: Remarkably High Carrier Mobilities and Large Diffusion Lengths. Nano Lett 2016; 16: 4838–4848. Zhao D, Chia EEM. Free Carrier, Exciton, and Phonon Dynamics in Lead-Halide Perovskites Studied with Ultrafast Terahertz Spectroscopy. Adv Opt Mater 2020; 8: 1900783. Bakker HJ, Skinner JL. Vibrational spectroscopy as a probe of structure and dynamics in liquid water. Chem Rev 2010; 110: 1498–1517. Zhu G, Lu W, Zhu J, Li Y, Guo L, Weng Y. Measuring the Carrier Dynamics of Photocatalyst Micrograins Using the Christiansen Effect. J Chem Phys 2017; 146: 234202. Nomura Y, Wang YT, Kozai T, Shirai H, Yabushita A, Luo CW et al. Single-shot detection of mid-infrared spectra by chirped-pulse upconversion with four-wave difference frequency generation in gases. Opt Express 2013; 21: 18249–18254. Calabrese C, Stingel AM, Shen L, Petersen PB. Ultrafast continuum mid-infrared spectroscopy: probing the entire vibrational spectrum in a single laser shot with femtosecond time resolution. Opt Lett 2012; 37: 2265. Cheng M, Reynolds A, Widgren H, Khalil M. Generation of tunable octave-spanning mid-infrared pulses by filamentation in gas media. Opt Lett 2012; 37: 1787–89. Baiz CR, Kubarych KJ. Ultrabroadband detection of a mid-IR continuum by chirped-pulse upconversion. Opt Lett 2011; 36: 187–189. Bjorklund GC. Effects of Focusing on Third-Order Nonlinear Processes in Isotropic Media. IEEE J Quantum Electron 1975; 11: 287–296. Tokmakoff A, Fayer MD, Dlott DD. Chemical Reaction Initiation and Hot-Spot Formation in Shocked Energetic Molecular Materials. J Phys Chem 1993; 97: 1901–1913. Klarskov P, Strikwerda AC, Iwaszczuk K, Jepsen PU. Experimental three-dimensional beam profiling and modeling of a terahertz beam generated from a two-color air plasma. New J Phys 2013; 15: 075012. Knorr J, Rudolf P, Nuernberger P. A comparative study on chirped-pulse upconversion and direct multichannel MCT detection. Opt Express 2013; 21: 30693. Lee KF, Nuernberger P, Bonvalet A, Joffre M. Removing cross-phase modulation from midinfrared chirped-pulse upconversion spectra. Opt Express 2009; 17: 18738–18744. Fuji T, Nomura Y. Generation of Phase-Stable Sub-Cycle Mid-Infrared Pulses from Filamentation in Nitrogen. Appl Sci 2013; 3: 122–138. Fuji T, Suzuki T. Generation of sub-two-cycle mid-infrared pulses by four-wave mixing through filamentation in air. Opt Lett 2007; 32: 3330–3332. Bergé L, Skupin S, Köhler C, Babushkin I, Herrmann J. 3D numerical simulations of THz generation by two-color laser filaments. Phys Rev Lett 2013; 110: 073901. Borodin A V., Panov NA, Kosareva OG, Andreeva VA, Esaulkov MN, Makarov VA et al. Transformation of THz spectra emitted from dual-frequency femtosecond pulse interaction in gases. Opt Lett 2013; 38: 1906–1908. Brewer SH, Franzen S. Optical properties of indium tin oxide and fluorine-doped tin oxide surfaces: correlation of reflectivity, skin depth, and plasmon frequency with conductivity. J Alloys Compd 2002; 338: 73–79. Gordon IE, Rothman LS, Hill C, Kochanov R V., Tan Y, Bernath PF et al. The HITRAN2016 molecular spectroscopic database. J Quant Spectrosc Radiat Transf 2017; 203: 3–69. Cole-Filipiak NC, Knepper R, Wood M, Ramasesha K. Sub-picosecond to Sub-nanosecond Vibrational Energy Transfer Dynamics in Pentaerythritol Tetranitrate. J Phys Chem Lett 2020; 11: 6664–6669. Yeh T-T, Shirai H, Tu C-M, Fuji T, Kobayashi T, Luo C-W. Ultrafast carrier dynamics in Ge by ultra-broadband mid-infrared probe spectroscopy. Sci Rep 2017; 7: 40492. Pravica M, Galley M, Kim E, Weck P, Liu Z. A far- and mid-infrared study of HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7- tetrazocine) under high pressure. Chem Phys Lett 2010; 500: 28–34. Grechko M, Hasegawa T, Angelo FD, Ito H, Turchinovich D, Nagata Y et al. Coupling between intra- and intermolecular motions in liquid water revealed by two- dimensional terahertz-infrared-visible spectroscopy. Nat Commun 2018; 9: 885. Yu CC, Chiang KY, Okuno M, Seki T, Ohto T, Yu X et al. Vibrational couplings and energy transfer pathways of water’s bending mode. Nat Commun 2020; 11: 5977. Lindner J, Cringus D, Pshenichnikov MS, Vöhringer P. Anharmonic bend-stretch coupling in neat liquid water. Chem Phys 2007; 341: 326–335. Tran H, Cunha A V., Shephard JJ, Shalit A, Hamm P, Jansen TLC et al. 2D IR spectroscopy of high-pressure phases of ice. J Chem Phys 2017; 147: 144501. Liu B, He C, Jin M, Ding D, Gao C. Time-resolved ultrafast carrier dynamics in CdTe quantum dots under high pressure. Phys Status Solidi Basic Res 2011; 248: 1102–1105. Lu DX, Wang YH, Li FF, Huang XL, Pan LY, Gong YB et al. Pressure-Dependent Relaxation Dynamics of Excitons in Conjugated Polymer Film. J Phys Chem C 2015; 119: 13194–13199. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3909502","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":274040124,"identity":"eca8a2b1-cee3-45cd-aeb0-e33a3e156c51","order_by":0,"name":"Yanqiang Yang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAArklEQVRIiWNgGAWjYPACG9K1pJGu5TAJag2O5xh+Lvh1Xp6/vfcAw88dxGg588ZYembfbcMZZ84lMPaeIUbLjRwDad6e2wkMQAYzYxtxWox/8/acS5C//4Z4LWbSPD8OJBjc4CFSi+SZZ2XWvA3JhhvP5CUc7CVGC9/x5M23ef7YycsdP3vwwU9itCgcyDBggLiHh+EAERoYGOQb0h8wMPyBaBkFo2AUjIJRgBUAABl6OvULbu/PAAAAAElFTkSuQmCC","orcid":"","institution":"National Key Laboratory of Shock Wave and Detonation Physics , Institute of Fluid Physics, China Academy of Engineering Physics","correspondingAuthor":true,"prefix":"","firstName":"Yanqiang","middleName":"","lastName":"Yang","suffix":""},{"id":274040125,"identity":"caec0cef-4c7e-4b7c-8631-c98fc9cd24a4","order_by":1,"name":"Gangbei Zhu","email":"","orcid":"","institution":"Institute of Fluid Physics, China Academy of Engineering Physics","correspondingAuthor":false,"prefix":"","firstName":"Gangbei","middleName":"","lastName":"Zhu","suffix":""},{"id":274040126,"identity":"1b54cba9-a4ba-46e3-a1b4-9920f6c3cf10","order_by":2,"name":"Yangyang Zeng","email":"","orcid":"","institution":"Institute of Fluid Physics, China Academy of Engineering Physics","correspondingAuthor":false,"prefix":"","firstName":"Yangyang","middleName":"","lastName":"Zeng","suffix":""},{"id":274040127,"identity":"236681d6-a48e-445c-9d93-0e0601ca40aa","order_by":3,"name":"Jian Mu","email":"","orcid":"","institution":"Institute of Fluid Physics, China Academy of Engineering Physics","correspondingAuthor":false,"prefix":"","firstName":"Jian","middleName":"","lastName":"Mu","suffix":""},{"id":274040128,"identity":"7f1b6190-3f63-4e9d-b7ce-b50d5c386813","order_by":4,"name":"Zhaoyang Zheng","email":"","orcid":"","institution":"Institute of Fluid Physics, China Academy of Engineering Physics","correspondingAuthor":false,"prefix":"","firstName":"Zhaoyang","middleName":"","lastName":"Zheng","suffix":""},{"id":274040129,"identity":"e017ba5a-683b-4499-ba14-121e039134b5","order_by":5,"name":"Guoyang Yu","email":"","orcid":"","institution":"Institute of Fluid Physics, China Academy of Engineering Physics","correspondingAuthor":false,"prefix":"","firstName":"Guoyang","middleName":"","lastName":"Yu","suffix":""}],"badges":[],"createdAt":"2024-01-30 01:15:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3909502/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3909502/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":51522420,"identity":"19b2ddcd-8b21-43f3-8633-5784c0fa0c34","added_by":"auto","created_at":"2024-02-23 04:18:28","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":77974,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram of the experimental setup of the time-resolved far-infrared full-spectrum spectroscopy system. WP, waveplate; DWP, dual-wavelength waveplate; PR, phase retarder; BBO, beta-barium borate; Si, silicon window; CM, concave mirror; PM1, PM2, PM3 and PM4, parabolic mirrors; Lens1, Lens2 and Lens3, lenses; BF, broadband short-pass filter. The waveplate is used to rotate the polarization of the fundamental laser to a vertical orientation. The polarizations of the fundamental and SHG laser are modified to be parallel by a dual-wavelength waveplate. Inset: schematic diagram of the DAC.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-3909502/v1/845caa2f5454af0d30b55a87.png"},{"id":51522417,"identity":"6cda2fb3-6228-4061-9f45-4f2952b5cd98","added_by":"auto","created_at":"2024-02-23 04:18:26","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":39853,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Spectrum of the infrared continuum, illustrating the presence of a DAC with a red line and the absence of a DAC with a black line. (b) Low-frequency and (c) high-frequency spectra of the continuum with a relative humility of 3% (black line) and 20% (orange line) are plotted along with the water vapor absorption spectrum from the HITRAN database (blue line).\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-3909502/v1/c82be43cf7dc4a456a7dd79d.png"},{"id":51522418,"identity":"31e0c776-be25-4ae5-8468-0df489fa2da6","added_by":"auto","created_at":"2024-02-23 04:18:27","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":76199,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Time-resolved infrared transient absorption spectrum of multi-photon-induced carriers in Ge at ambient pressure after excitation at 1280 cm\u003csup\u003e-1\u003c/sup\u003e. (b) Experimental (open squares) and fitted (red curve) cross-correlation trace S at 700 cm\u003csup\u003e-1\u003c/sup\u003e. (c) t\u003csub\u003e0\u003c/sub\u003e (open circles) and (d) IRF (open triangles) of each frequency component as extracted from cross-correlation in Ge.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-3909502/v1/5e5ed1ddc406f72bf16c1b05.png"},{"id":51522419,"identity":"cf728fbf-9a21-4a3a-b847-c01b5264878b","added_by":"auto","created_at":"2024-02-23 04:18:27","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":49284,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Stack plots of transient absorption spectra (DmOD) of HMX at 400ps delay time at various pressures. Baselines of the spectra are displaced vertically by the pressure at which the spectra were acquired. The infrared absorbance spectrum (grey curve) is plotted on the bottom. The spectra in the 200 to 900 cm\u003csup\u003e-1\u003c/sup\u003e range are multiplied by a factor of 3 for clarity. (b-e) The dynamics of representative in-plane bending vibration near 600 cm\u003csup\u003e-1\u003c/sup\u003e of nitro groups in crystalline HMX for several different pressures: (b) ambient pressure, (c) 2.4 GPa, (d) 4.5 GPa, and (e) 7.3 GPa. The open squares in (b-e) represent the experimental data of the dynamics, while the curves represent the fitted traces. (f) Pressure dependence of the fitted time constant. Error bars represent the fitting error of the time constant.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-3909502/v1/8e7074a8265d593a6520d4b7.png"},{"id":53906411,"identity":"af184f49-a3e9-4fa8-89ab-57d201240fa4","added_by":"auto","created_at":"2024-04-02 05:08:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":431032,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3909502/v1/1b48ccfc-1c9f-42ab-94bc-679f105611f8.pdf"}],"financialInterests":"(Not answered)","formattedTitle":"High-Pressure Ultrafast Time-Resolved Far-Infrared Full-spectrum Spectroscopy with Air-Based Upconversion","fulltext":[{"header":"Full Text","content":"\u003cp\u003eHigh-pressure time-resolved spectroscopy has gained widespread applications in various fields, including materials science, chemistry, and geophysics\u003csup\u003e1\u0026ndash;8\u003c/sup\u003e. It is an essential tool for studying dynamic processes occurring in materials under high-pressure conditions, such as those encountered deep within the Earth\u0026rsquo;s interior or during shock compression experiments. Particularly, high-pressure time-resolved infrared spectroscopy is a powerful method for investigating the kinetics and mechanisms of chemical reactions, phase transitions, and structural transformations under extreme pressure\u003csup\u003e9\u003c/sup\u003e. Its capability to capture ultrafast molecular dynamics provides valuable insights into energy flow, structural changes, and intermolecular interactions.\u003c/p\u003e\n\u003cp\u003eDespite its significance, there have been only a few prior studies of time-resolved infrared spectroscopy under high pressure. In 2009, nanosecond time-resolved transient infrared spectroscopy in the mid-infrared region was used to investigate the photolysis of TATB under high pressure\u003csup\u003e9\u003c/sup\u003e. In 2014, sub-picosecond time-resolved two-dimensional infrared spectroscopy in the spectral range of 2200-2700 cm\u003csup\u003e-1\u003c/sup\u003e with hole-burning methods was employed to study water dynamics under high pressure\u003csup\u003e10\u003c/sup\u003e. In 2018, sub-picosecond time-resolved optical pump infrared probe measurement was conducted to study the phase transition of VO\u003csub\u003e2\u003c/sub\u003e probed with 10-\u0026mu;m infrared pulses under high pressure\u003csup\u003e11\u003c/sup\u003e. In 2021, sub-picosecond time-resolved THz spectroscopy was used to study the dynamics of photo-induced carriers in GaAs under high pressure\u003csup\u003e12\u003c/sup\u003e. However, these infrared experiments were constrained by the narrow bandwidth of the infrared pulses used, allowing only single bands of vibrations to be probed. This limitation precluded a global view of dynamics.\u003c/p\u003e\n\u003cp\u003eFurthermore, due to a shortage of sensitive detectors currently available, there are constraints in conducting time-resolved spectral measurements in the far-infrared spectral region (~50\u0026ndash;600 cm⁻\u0026sup1;, ~1.5\u0026ndash;18 THz) \u003csup\u003e13\u003c/sup\u003e. This spectral region holds unique importance in the fields of the material science of physics\u003csup\u003e14\u003c/sup\u003e, chemistry\u003csup\u003e15\u003c/sup\u003e and biology\u003csup\u003e16\u003c/sup\u003e, given the presence of various excitations such as molecular vibrations, molecular rotations, phonons, carriers, Cooper pairs, excitons, spin-orbit coupling resonating within this energy range\u003csup\u003e17\u003c/sup\u003e. For instance, lattice modes and doorway modes of energetic molecular crystals play crucial roles in the shock detonation initiation of explosives, located in the 0-200 cm\u003csup\u003e-1\u003c/sup\u003e and 200-800 cm\u003csup\u003e-1\u003c/sup\u003e range, respectively \u003csup\u003e18,19\u003c/sup\u003e. Changes in the population distribution of these modes during shock-induced detonation are expected to lead to time-dependent changes in the far-infrared vibrational spectrum. While conventional two-dimensional time-resolved terahertz spectroscopy (2D TRTS) can be employed for acquiring time-resolved spectra in far-infrared \u003csup\u003e14\u003c/sup\u003e, it is time-consuming, necessitating the collection of hundreds of data points along the THz detection delay for each pump-probe delay\u003csup\u003e20\u0026ndash;22\u003c/sup\u003e. Additionally, due to the absorption from phonon modes of electrooptic crystals, real-time detection of the full-spectrum far-infrared spectrum poses a challenge in single-shot terahertz time-domain spectroscopy (THz TDS) using electro-optics sampling (EOS) detection, with most of work being done between 0.5 and 3 THz (between 20 and 100 cm\u003csup\u003e-1\u003c/sup\u003e)\u003csup\u003e14\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;In this paper, we present the first high-pressure ultrafast time-resolved full-spectrum far-infrared spectroscopy spanning from \u0026lt;50 to \u0026gt;1800 cm\u003csup\u003e-1\u003c/sup\u003e. The generation of the air-plasmon-based infrared continuum is effectively achieved by utilizing two-color laser filaments with a commercial femtosecond laser. This ultrabroadband continuum serves as the probe light source, providing sub-cycle coherent infrared pulses that benefit time-resolved pump-probe measurements\u003csup\u003e23\u003c/sup\u003e. In contrast to previous works, where the mid-infrared continua were obtained \u003csup\u003e24\u0026ndash;27\u003c/sup\u003e, the spectrum of the infrared continuum in this work is extended to the far-infrared using 100-fs laser pulses. A single-shot nonlinear upconversion detection scheme\u003csup\u003e28\u003c/sup\u003e is employed to detect the entire spectrum of the infrared continuum in real-time. To avoid light absorption by the nonlinear crystal, air is selected as the nonlinear medium. Given the isotropy of air, the third-order nonlinear optical process is applied in this method \u003csup\u003e29\u003c/sup\u003e. This process results in the upconversion of infrared light to visible light, capturing the complete spectrum of the infrared continuum by simply shifting the spectrum of the upconverted visible light, recorded using a high-performance visible dispersive spectrometer. Consequently, nonlinear spectral upconversion is achieved in a single shot, allowing direct detection across the entire source spectral range in the frequency domain without the need for Fourier transformation as required in conventional THz TDS. Compared to commercial FTIR spectrometers and infrared dispersive spectrometers with an MCT array detector, this method not only enables simultaneous detection of both mid-infrared and far-infrared without the need for additional mid- and far-infrared detectors, but also allows for measurement of the entire infrared spectrum in a single shot. To showcase the advantages of this system, we present the full transient far-infrared absorption spectrum of the complete set of vibrational fingerprint modes in the energetic molecular microcrystal of HMX, a typical energetic molecular material, following excitation of the stretching vibration of nitro groups under the conditions of greatest interest: the regime of relatively weak shock waves (pressure, p = 1-10 GPa) characteristic of accidents\u003csup\u003e30\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThe schematic of the experimental setup is shown in Fig. 1. A commercial Ti:sapphire amplifier (800nm, 1kHz) is employed to provide 100-fs pulses with an energy of 6mJ, which is subsequently split to three beams with an energy ratio of 1:1:4. The first beam is used to induce the infrared continuum generation by driving the air plasmon. The nonlinear crystal BBO is used for second harmonic generation (SHG) of the fundamental laser, achieving a 5% conversion efficiency. A collinear configuration, where the fundamental and SHG beams are not separated, is used to stabilize the output intensity. The time dispersion of the fundamental and SHG pulses is compensated by carefully rotating a phase retarder. A 3-mm length plasma is generated by focusing the pulses of the fundamental and SHG laser in air. A conical infrared continuum emission is produced through the light-matter interaction of the two-color laser field and air plasma\u003csup\u003e31\u003c/sup\u003e. A pulse energy of 50 nJ is measured using a pyroelectric joulemeter (J-10mb-e, Coherent) behind a silicon window, which filters the continuum from the residual light. The silicon window reflects half of the energy, indicating that the total energy of the produced infrared continuum is approximately 100 nJ. The continuum is focused onto a DAC with a culet size of 600\u0026mu;m by a parabolic mirror, with a focal spot size of 300 \u0026mu;m. The continuum passing through the DAC is then collimated by a parabolic mirror, and its spectrum is detected by the second beam.\u003c/p\u003e\n\u003cp\u003eThe second beam, used as detection light, is initially stretched to generate chirped pulses with a time duration of 10ps using a grating stretcher, ensuring high detection spectral resolution. Subsequently, it is focused, by a lens to the air in the detection cell through the 3-mm hole in the center of a parabolic mirror. The infrared continuum is focused to overlap the focal spot of the chirped beam by the parabolic mirror. The field of the infrared continuum induces a four-wave different frequency (FWDFG) process, generating a visible mixture light with a pulse energy of several picojoules. The frequency of the mixture light is expressed as \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\omega }_{vis}=2{\\omega }_{nir}-{\\omega }_{con}\\)\u003c/span\u003e\u003c/span\u003e, with \u003cem\u003e\u0026omega;\u003c/em\u003e\u003csub\u003e\u003cem\u003enir\u003c/em\u003e\u003c/sub\u003e and \u003cem\u003e\u0026omega;\u003c/em\u003e\u003csub\u003e\u003cem\u003econ\u003c/em\u003e\u003c/sub\u003e denoting frequencies of the chirped light and the infrared continuum, respectively. The spectrum of the visible mixture light is recorded using an optical spectrometer and a commercial EMCCD detector after filtering out the residual chirped light with a broadband short-pass filter. Then, the entire spectrum of the infrared continuum can be obtained by simply shifting the spectrum of the visible light. The delay line \u0026tau;\u003csub\u003e1\u003c/sub\u003e is used to find out the temporal overlap of the chirped pulses and continuum pulses, and it doesn\u0026rsquo;t need to scan during detection, which means that the spectrum of the infrared continuum can be obtained by a single pulse. According to the four-wave mixing generation theory\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e, the derived FWDFG efficiency \u003cem\u003eF\u003c/em\u003e\u003csub\u003e\u003cem\u003e2\u003c/em\u003e\u003c/sub\u003e is governed by an integration given as\u003c/p\u003e\n\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equa\" class=\"mathdisplay\"\u003e$$\\begin{array}{c}{F}_{2}={\\left|{\\int }_{-l}^{l}dx\\frac{\\text{exp}\\left(-i\\varDelta kx\\right)}{1+{\\left(2x/k{}_{0}^{2}\\right)}^{2}}\\right|}^{2} \\left(1\\right)\\end{array}$$\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003ewhere 2\u003cem\u003el\u003c/em\u003e is the length of the FWDFG region, \u003cem\u003ek\u003c/em\u003e and \u003cem\u003e\u0026zeta;\u003c/em\u003e\u003csub\u003e0\u003c/sub\u003e is the wave vector and beam-waist radius of the generated beam, respectively, and \u0026Delta;\u003cem\u003ek\u003c/em\u003e\u0026thinsp;~\u0026thinsp;0 is the wave-vector mismatch in air. In accordance with Eq.\u0026nbsp;(1), it is evident that efficiency is only dependent upon geometric parameters and remains independent on the frequency and intensity of infrared light. This characteristic implies the potential of FWDFG for detecting transient changes in infrared light intensity for the entire infrared range.\u003c/p\u003e\n\u003cp\u003eIt is noticed that, given the utilization of chirped pulses for upconverting the infrared, consideration must be given to the cross-phase distortions within the spectrum of the visible mixture light. These cross-phase modulations are addressed using algorithms as detailed in literatures \u003csup\u003e\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e. Briefly, the compensation involves adjusting the phase of the Fourier transform of the measured spectrum through the time-dependent phase of the chirped pulse \u003csup\u003e\u003cspan class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e given as\u003c/p\u003e\n\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equb\" class=\"mathdisplay\"\u003e$$\\begin{array}{c}\\left(t\\right)=\\frac{{\\omega }^{\\left(1\\right)}{t}^{2}}{2} \\left(2\\right)\\end{array}$$\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003ewhere, the chirped rate parameter \u003cem\u003e\u0026omega;\u003c/em\u003e\u003csup\u003e\u003cem\u003e(1)\u003c/em\u003e\u003c/sup\u003e is 4 rad/ps\u003csup\u003e2\u003c/sup\u003e in this work, corresponding to a second-order spectral-phase parameter of 0.25 ps\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThe third beam with a pulse energy of 4mJ is used to pump an optical parameter amplifier, the outputs of which are used to generate excitation pulses. The excitation pulses are used to excite the sample in transient spectrum measurement. The pump beam is focused to the DAC by a lens through the 3-mm hole in the center of PM2. The focal spot size of the pump beam is 500\u0026micro;m, slightly larger than that of the infrared continuum. The Delay line is used to vary the time delay between the excitation and probe pulses. The optical path for infrared pulse is purged with dry air or nitrogen gas, shown as the light grey area in Fig.\u0026nbsp;1.\u003c/p\u003e\n\u003cp\u003eFirst, the spectrum of the continuum light source was measured. The spectra of the infrared continuum through no sample cell and through a DAC are shown in Fig.\u0026nbsp;2(a). Here, an enhancement in the far-infrared region of the spectrum extends the infrared continuum, spanning six octaves and covering nearly the entire mid- and far- infrared range (\u0026lt;\u0026thinsp;30 to \u0026gt;\u0026thinsp;2400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e or \u0026lt;\u0026thinsp;1 to \u0026gt;\u0026thinsp;72 THz). Compared with the previous work\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e, the whole spectrum in this work is red-shifted, achieved by employing a laser pulse with a longer duration because the center frequency of the infrared continuum is determined by the duration of laser pulses. According to the infrared continuum theory\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e, the contribution of the four-wave mixing process dominates the generation of the infrared continuum in the long-filament regime. Therefore, the electric field can be expressed as\u003c/p\u003e\n\u003cdiv id=\"Equc\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equc\" class=\"mathdisplay\"\u003e$$\\begin{array}{c}{E}_{ir}\\left(\\omega \\right)\\propto {\\omega }^{2}F(E\\left(t{)}^{3}\\right) (3)\\end{array}$$\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003ewhere \u003cem\u003eF\u003c/em\u003e(\u003cem\u003eE\u003c/em\u003e(t)\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e) is the Fourier transform of \u003cem\u003eE\u003c/em\u003e(t)\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e, \u003cem\u003eE\u003c/em\u003e(\u003cem\u003et\u003c/em\u003e) denotes the electric field with the fundamental and its SHG \u003csup\u003e\u003cspan class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e. Given that:\u003c/p\u003e\n\u003cdiv id=\"Equd\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equd\" class=\"mathdisplay\"\u003e$$\\begin{array}{c}E\\left(t\\right)={E}_{0}\\left(\\sqrt{1-r}\\text{exp}\\left(-\\frac{{t}^{2}}{{{t}_{p}}^{2}}\\right)\\text{cos}\\left({\\omega }_{0}t\\right)+\\sqrt{r}\\text{exp}\\left(-\\frac{2{t}^{2}}{{{t}_{p}}^{2}}\\right)\\text{cos}\\left(2{\\omega }_{0}t\\right)\\right) \\left(4\\right)\\end{array}$$\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003ewhere \u003cem\u003et\u003c/em\u003e\u003csub\u003e\u003cem\u003ep\u003c/em\u003e\u003c/sub\u003e, r and \u0026omega;\u003csub\u003e0\u003c/sub\u003e denote the pulse duration parameter, the SHG intensity fraction, and the fundamental central frequency. Thus, \u003cem\u003eE\u003c/em\u003e\u003csub\u003e\u003cem\u003eir\u003c/em\u003e\u003c/sub\u003e(\u0026omega;)\u0026prop;\u0026omega;\u003csup\u003e2\u003c/sup\u003eexp(-\u0026omega;\u003csup\u003e2\u003c/sup\u003e/(4/\u003cem\u003et\u003c/em\u003e\u003csub\u003e\u003cem\u003ep\u003c/em\u003e\u003c/sub\u003e)\u003csup\u003e2\u003c/sup\u003e), and we expect a maximum at \u0026omega;\u0026thinsp;=\u0026thinsp;4/\u003cem\u003et\u003c/em\u003e\u003csub\u003e\u003cem\u003ep\u003c/em\u003e\u003c/sub\u003e, which is inversely proportional to the pulse duration. A longer pulse duration results in a higher contribution of low-frequency component, consistent with previous simulation work\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e. For 100-fs pulses with \u003cem\u003et\u003c/em\u003e\u003csub\u003e\u003cem\u003ep\u003c/em\u003e\u003c/sub\u003e=85 fs, the central frequency is around 250 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, which agrees well with the experimental result. The broadening of the high-frequency component of the continuum is likely a result of the spectral self-broadening of the fundamental pulses.\u003c/p\u003e\n\u003cp\u003eThe low-frequency part of the continuum spectrum with a sub-mm-scale spot size is attenuated slightly by the DAC with a small clear aperture, while the high-frequency part is absorbed by the DAC due to the intrinsic absorption band of the diamond in the 2000 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e region, leading to narrowing of the measurable spectral range: from \u0026lt;\u0026thinsp;50 to \u0026gt;\u0026thinsp;1800 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The spectrum exhibits a smooth overall profile, indicating that this source is well-suited for use as probe light. The fine structures due to the absorption of silicon window at ~\u0026thinsp;610 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and silica protective overcoat on mirrors at ~\u0026thinsp;1250 cm\u003csup\u003e\u0026minus;\u0026thinsp;138\u003c/sup\u003e are evidently observed. The absorption lines of water vapor in the 200 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 1600 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e regions have also been clearly observed in Fig.\u0026nbsp;2(b) and Fig.\u0026nbsp;2(c), in good agreement with the water vapor absorption spectrum from the HITRAN database\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e39\u003c/span\u003e\u003c/sup\u003e broadened by a Gaussian function with a 4-cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e bandwidth, which indicates that the spectral resolution of this system is around 4 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTo accurately determine the zero delay time and instrumental response function (IRF) of this system, cross-correlation measurements using a undoped germanium (Ge) wafer was performed at ambient pressure in the DAC, as previously employed in mid-infrared range\u003csup\u003e2640\u003c/sup\u003e. The multi-photon absorption of mid-infrared excitation pulses generates the photo-induced carriers in the Ge wafer, leading to a transient absorption in the far-infrared region, as shown in Fig.\u0026nbsp;3(a). The recombination relaxation lifetime of photo-induced carriers is on the 1 ns time scale, in agreement with the experimental result ever reported \u003csup\u003e\u003cspan class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e. The broadband transient spectrum around t\u0026thinsp;=\u0026thinsp;0 contributes to the Kerr effect, a nonlinear process caused by changes in refractive index due to the pump pulse propagation. The cross-correlation trace S for the Kerr effect can be fitted by convoluting a Gaussian function with a bi-exponential decay, given by\u003c/p\u003e\n\u003cdiv id=\"Eque\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Eque\" class=\"mathdisplay\"\u003e$$S=\\text{exp}\\left(-\\frac{{\\left(t-{t}_{0}\\right)}^{2}}{2 {d}^{2}}\\right)\\otimes h\\left(t-{t}_{0}\\right)\\left({a}_{1}\\text{exp}\\left(-\\frac{t-{t}_{0}}{{t}_{1}}\\right)+{a}_{2}\\text{exp}\\left(-\\frac{t-{t}_{0}}{{t}_{2}}\\right)+{a}_{3}\\right)$$\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Equf\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equf\" class=\"mathdisplay\"\u003e$$={a}_{1}\\left(1+\\text{erf}\\left(\\frac{t-\\left({t}_{0}+\\frac{{d}^{2}}{{t}_{1}}\\right)}{\\sqrt{2}d}\\right)\\right)\\text{exp}\\left(-\\frac{t-\\left({t}_{0}+\\frac{{d}^{2}}{2{t}_{1}}\\right)}{{t}_{1}}\\right)$$\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Equg\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equg\" class=\"mathdisplay\"\u003e$$+{a}_{2}\\left(1+\\text{erf}\\left(\\frac{t-\\left({t}_{0}+\\frac{{d}^{2}}{{t}_{2}}\\right)}{\\sqrt{2}d}\\right)\\right)\\text{exp}\\left(-\\frac{t-\\left({t}_{0}+\\frac{{d}^{2}}{2{t}_{2}}\\right)}{{t}_{2}}\\right)$$\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Equh\" class=\"Equation\"\u003e\n\u003cdiv id=\"FileID_Equh\" class=\"mathdisplay\"\u003e$$\\begin{array}{c}+{a}_{3}\\left(1+\\text{erf}\\left(\\frac{t-{t}_{0}}{\\sqrt{2}d}\\right)\\right) \\left(5\\right)\\end{array}$$\u003c/div\u003e\n\u003c/div\u003e\n\u003cp\u003ewhere t\u003csub\u003e0\u003c/sub\u003e denotes the zero delay time, d\u0026thinsp;=\u0026thinsp;IRF/2, h(t) is the Heaviside unit step function, and a\u003csub\u003e1\u003c/sub\u003e, a\u003csub\u003e2\u003c/sub\u003e, a\u003csub\u003e3\u003c/sub\u003e and t\u003csub\u003e1\u003c/sub\u003e, t\u003csub\u003e2\u003c/sub\u003e are pre-exponential factors and time constants of the exponential function. Figure\u0026nbsp;3(b) shows a representative cross-correlation trace at 700 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. As seen in Fig.\u0026nbsp;3(c), the change of t\u003csub\u003e0\u003c/sub\u003e with frequency indicates that the relative chirp of the infrared continuum is less than 90 fs across the entire spectral range. This small chirp is attributed to the low dispersion of diamond. Figure\u0026nbsp;3(d) shows that IRF of each frequency component remains around 0.3 ps for all frequencies, mainly determined by the time duration of the pump pulse. Additionally, the signal observed in Fig.\u0026nbsp;3(a) at approximately 1280 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e is a coherent artificial signal resulting from the up-conversion signal of the scattered pump light.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAlthough the Ge system can serve as a good benchmark for our new technique, the carrier relaxation exhibits similar behavior at different frequencies and can be detected by conventional narrow-band infrared pump-probe spectroscopy using optical parametric amplifiers. To illustrate the capability of full-spectrum infrared spectroscopy, we conducted transient vibrational spectrum measurements of the complete set of vibrational fingerprint modes to study vibrational coupling dynamics in microcrystalline HMX under different pressures in DAC. In this case, both a broad spectral range and high spectral resolution are necessary for effectively detecting and analyzing the overall dynamics of the distinguishable vibrational modes under high pressure.\u003c/p\u003e\n\u003cp\u003eThe center frequency of the excitation pulses is tuned to 1280 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to resonate with the nitro group symmetric stretching vibration of the HMX crystal. The pressure-dependent transient spectra covering the entire fingerprint region of HMX at 400ps delay time under four pressures in the 200\u0026minus;1700 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e range following excitation of the stretching vibration of nitro groups are presented in Fig.\u0026nbsp;4(a). A negative transient absorption value is assigned to bleach features (resulting from stimulated emission or loss of ground state absorption), while a positive value is assigned to excited state absorption features. The transient absorbance peaks evidently exhibit a blue shift and decrease as the pressure increases, as shown in Fig.\u0026nbsp;4(a), as their steady-state absorbance peaks broaden, weaken and blue-shift with increasing pressure\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e42\u003c/span\u003e\u003c/sup\u003e. Attaining this broadband far-infrared time-resolved spectrum would be challenging and time-consuming by conventional 2D TRTS or infrared dispersive spectrometer, while here we implement the real-time full-spectrum far-infrared (or THz) transient spectrum measurement using single-shot detection by air-based upconversion method.\u003c/p\u003e\n\u003cp\u003eAs regards the time evolution of these fingerprint modes, Figs.\u0026nbsp;4(b-e) display the dynamics traces of the representative doorway mode near 600 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, one of the three near-degenerate in-plane bending vibrations in the 600 to 700 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e range. These traces are fitted with a mono-exponential curve. The rising signals represent the vibrational energy transfer from the nitro stretching to the bending vibration. This process emerges after t\u0026thinsp;=\u0026thinsp;0 and continues until thermal equilibrium is reached. Figure\u0026nbsp;4(f) indicates that the time constant, ~\u0026thinsp;100 ps at ambient pressure, decreases with pressure and is reduced by a factor of 10 under 7.3 GPa. This observation reveals that the coupling is enhanced under compression, consistent with the early theory proposed by Fayer and Dlott\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e, which stated that the principal effect of pressure on the transfer rate was the increase in the anharmonic coupling. It is suggested that the pressure-enhanced coupling between vibrational modes and doorway modes determines the sensibility of energetics under relatively weak shock waves (pressure p\u0026thinsp;=\u0026thinsp;1\u0026minus;10GPa).\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn conclusion, we have introduced a novel high-pressure, real-time ultrafast time-resolved infrared spectroscopy capable of spanning multiple octaves (from \u0026lt;\u0026thinsp;50 to \u0026gt;\u0026thinsp;1800 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and covering the entire far-infrared range. The far-infrared continuum is generated through two-color laser filaments using 100-fs pulses and is detected using single-shot detection with air-based up-conversion. Transient spectra in the 30\u0026ndash;2400 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e range can be acquired with a resolution of a few cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The six-octave spanning spectrum covers the entire molecular fingerprint region (50\u0026ndash;1500 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and a significant portion of the functional group region (1500\u0026ndash;4000 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). With a full-spectrum infrared source, this detection method can essentially cover the entire infrared range. Combining this spectroscopy with high-pressure DAC technology, we investigate the vibrational coupling of all fingerprint modes in microcrystalline HMX following infrared excitation under various pressures, revealing pressure-dependent coupling enhancement between the excited modes and doorway modes. This observation highlights the effectiveness of our method in capturing comprehensive vibrational changes within energetic molecular systems.\u003c/p\u003e\n\u003cp\u003eFurthermore, the ability to probe the entire infrared spectrum under high pressure in a single laser shot will facilitate the study of a broader range of phenomena beyond vibrational coupling in energetic materials. For example, it can be used to investigate energy transfer between high- and low-frequency vibrational modes in other molecular systems such as the vibrational coupling between the bending and liberating modes in water\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e43\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e45\u003c/span\u003e\u003c/sup\u003e or the lattice modes of high-pressure phases of ice\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e46\u003c/span\u003e\u003c/sup\u003e. It can also be applied to study carrier or exciton relaxation with broad spectral changes and their coupling with phonons in quantum dots\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e,\u003cspan class=\"CitationRef\"\u003e47\u003c/span\u003e\u003c/sup\u003e, 2D materials\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e48\u003c/span\u003e\u003c/sup\u003e and bulk semiconductors\u003csup\u003e\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. We believe that this novel spectroscopy approach holds great potential for future research.\u003c/p\u003e\n"},{"header":"Methods","content":"\n\u003ch3\u003eSample preparation\u003c/h3\u003e\n\u003cp\u003eThe HMX sample powder was placed on one of the diamond flats and then gently pressed to the desired thickness (generally a few \u0026micro;m because of the strong mid infrared absorption). For pressure-loading measurements, stainless steel gaskets with an initial thickness of 200\u0026micro;m were indented to about 60\u0026micro;m, a hole with an initial diameter of 300\u0026micro;m was drilled in the center of the indentation, and a micro ruby ball was placed on the edge of the pressure chamber as pressure sensors as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The preindented thickness was chosen to be much larger than the sample thickness to prevent the diamonds from damaging each other under load. The remainder of the gasket hole was filled with the pressure-transmitting medium KBr.\u003c/p\u003e \u003cdiv id=\"Sec2\" class=\"Section2\"\u003e \u003ch2\u003eTime-resolved absorption spectrum measurement\u003c/h2\u003e \u003cp\u003eIn time-resolved absorption spectrum measurements, a pulse-to-pulse scheme was used, wherein a mechanics chopper operated at 500 Hz to modulate the excitation beam. The transient signal is expressed as the spectral absorbance change S(ω)\u0026thinsp;=\u0026thinsp;log(Σ\u003cem\u003eI\u003c/em\u003e\u003csub\u003e2i\u003c/sub\u003e/Σ\u003cem\u003eI\u003c/em\u003e\u003csub\u003e2i\u0026thinsp;+\u0026thinsp;1\u003c/sub\u003e), where \u003cem\u003eI\u003c/em\u003e\u003csub\u003e2i\u003c/sub\u003e and \u003cem\u003eI\u003c/em\u003e\u003csub\u003e2i\u0026thinsp;+\u0026thinsp;1\u003c/sub\u003e represent the spectral intensity of the even and odd probe pulses, respectively. Meanwhile, \u003cem\u003eI\u003c/em\u003e\u003csub\u003e2i\u003c/sub\u003e and \u003cem\u003eI\u003c/em\u003e\u003csub\u003e2i\u0026thinsp;+\u0026thinsp;1\u003c/sub\u003e represent the situations without and with excitation, respectively.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eCONFLICT OF INTEREST\u003c/h2\u003e \u003cp\u003eThe authors declare no conflict of interest.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAUTHOR CONTRIBUTIONS\u003c/h2\u003e \u003cp\u003eThe main setup was designed and built by GZ and YZ. The measurements were taken by GZ, YZ and JM. The DAC samples were prepared by YZ and GY. The data acquisition and analysis programs were written by GZ. ZZ offered assistance in theoretical analysis of experiment data. GZ and YY coordinated the project and wrote the manuscript. All authors participated in the discussion of results and reviewed the final manuscript.\u003c/p\u003e\u003ch2\u003eACKNOWLEDGEMENTS\u003c/h2\u003e \u003cp\u003eThis research was financially supported by the National Natural Science Foundation of China (Grant No. U2030113) and by the National Key Laboratory of Shockwave and Detonation Physics (Grant No. 2021JCJQLB05712).\u003c/p\u003e\u003ch2\u003eDATA AVAILABILITY\u003c/h2\u003e \u003cp\u003eThe data that support the findings of this study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eCheng P, Wang Y, Ye T, Chu L, Yang J, Zeng H \u003cem\u003eet al.\u003c/em\u003e Semiconductor-metal transition in lead iodide under pressure. Appl Phys Lett 2022; 120: 212104.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDu L, Shi X, Duan M, Shi Y. Pressure-Induced Tunable Charge Carrier Dynamics in Mn-Doped CsPbBr3 Perovskite. Materials (Basel) 2022; 15: 6984.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu YL, Yin X, Hasaien JZL, Tian ZY, Ding Y, Zhao J. On-site in situ high-pressure ultrafast pump-probe spectroscopy instrument. Rev Sci Instrum 2021; 92: 113002.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheng JC, Pan LY, Huang XL, Huang YP, Wang YH, Xu SP \u003cem\u003eet al.\u003c/em\u003e Interparticle spacing effect among quantum dots with high-pressure regulation. Nanomaterials 2021; 11: 1\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTsuchiya S, Nakagawa K, Yamada J, Toda Y. Carrier Relaxation Dynamics in the Organic Superconductor κ-(BEDT-TTF)2Cu(NCS)2 Under Pressure. J Supercond Nov Magn 2016; 29: 3071\u0026ndash;3074.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eH\u0026eacute;bert P, Saint-Amans C. Study of the laser-induced decomposition of energetic materials at static high-pressure by time-resolved absorption spectroscopy. J Phys Conf Ser 2014; 500: 022002.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu B, He C, Jin M, Wang Q, Lin SH, Ding D. High pressure effect on the ultrafast energy relaxation rate of LDS698 (C19H23N2O4Cl) in a solution. OE 2010; 18: 6863\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGump J, Parker L, Peiris SM, Gump J, Parker L, Peiris SM. HMX (Beta Phase): Laser-Ignited Reaction Kinetics and Isothermal Equations of State. Shock compression Condens matter 2003; 706: 967\u0026ndash;972.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGlascoe EA, Zaug JM, Armstrong MR, Crowhurst JC, Grant CD, Fried LE. Nanosecond time-resolved and steady-state infrared studies of photoinduced decomposition of TATB at ambient and elevated pressure. J Phys Chem A 2009; 113: 5881\u0026ndash;5887.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFanetti S, Lapini A, Pagliai M, Citroni M, Di Donato M, Scandolo S \u003cem\u003eet al.\u003c/em\u003e Structure and dynamics of low-density and high-density liquid water at high pressure. J Phys Chem Lett 2014; 5: 235\u0026ndash;240.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBraun JM, Schneider H, Helm M, Mirek R, Boatner LA, Marvel RE \u003cem\u003eet al.\u003c/em\u003e Ultrafast response of photoexcited carriers in VO2 at high-pressure. New J Phys 2018; 20: 083003.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXu S, Huang D, Liu Z, Zhang K, Jiang H, Gou H \u003cem\u003eet al.\u003c/em\u003e Hydrostatic pressure effect of photocarrier dynamics in GaAs probed by time-resolved terahertz spectroscopy. OE 2021; 29: 14058\u0026ndash;14068.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFriš P, Dubroka A. Vacuum variable-angle far-infrared ellipsometer. Appl Surf Sci 2017; 421: 430\u0026ndash;434.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchmuttenmaer CA. Exploring dynamics in the far-infrared with terahertz spectroscopy. Chem Rev 2004; 104: 1759\u0026ndash;1779.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHaran G, Sun WD, Wynne K, Hochstrasser RM. Femtosecond far-infrared pump-probe spectroscopy: A new tool for studying low-frequency vibrational dynamics in molecular condensed phases. Chem Phys Lett 1997; 274: 365\u0026ndash;371.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVatansever F, Hamblin MR. Far infrared radiation (FIR): Its biological effects and medical applications. Photonics Lasers Med 2012; 1: 255\u0026ndash;266.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBasov DN, Averitt RD, Marel D van der, Dressel M, Haule K. Electrodynamics of correlated electron materials. Rev Mod Phys 2011; 83: 471.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBernstein J. Ab initio study of energy transfer rates and impact sensitivities of crystalline explosives. J Chem Phys 2018; 148: 084502.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYe S, Koshi M. Theoretical Studies of Energy Transfer Rates of Secondary Explosives. J Phys Chem B 2006; 110: 18515\u0026ndash;18520.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVald\u0026eacute;s Aguilar R, Qi J, Brahlek M, Bansal N, Azad A, Bowlan J \u003cem\u003eet al.\u003c/em\u003e Time-resolved terahertz dynamics in thin films of the topological insulator Bi2Se3. Appl Phys Lett 2015; 106: 011901.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYettapu GR, Talukdar D, Sarkar S, Swarnkar A, Nag A, Ghosh P \u003cem\u003eet al.\u003c/em\u003e Terahertz Conductivity within Colloidal CsPbBr3 Perovskite Nanocrystals: Remarkably High Carrier Mobilities and Large Diffusion Lengths. Nano Lett 2016; 16: 4838\u0026ndash;4848.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao D, Chia EEM. Free Carrier, Exciton, and Phonon Dynamics in Lead-Halide Perovskites Studied with Ultrafast Terahertz Spectroscopy. Adv Opt Mater 2020; 8: 1900783.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBakker HJ, Skinner JL. Vibrational spectroscopy as a probe of structure and dynamics in liquid water. Chem Rev 2010; 110: 1498\u0026ndash;1517.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhu G, Lu W, Zhu J, Li Y, Guo L, Weng Y. Measuring the Carrier Dynamics of Photocatalyst Micrograins Using the Christiansen Effect. J Chem Phys 2017; 146: 234202.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNomura Y, Wang YT, Kozai T, Shirai H, Yabushita A, Luo CW \u003cem\u003eet al.\u003c/em\u003e Single-shot detection of mid-infrared spectra by chirped-pulse upconversion with four-wave difference frequency generation in gases. Opt Express 2013; 21: 18249\u0026ndash;18254.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCalabrese C, Stingel AM, Shen L, Petersen PB. Ultrafast continuum mid-infrared spectroscopy: probing the entire vibrational spectrum in a single laser shot with femtosecond time resolution. Opt Lett 2012; 37: 2265.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheng M, Reynolds A, Widgren H, Khalil M. Generation of tunable octave-spanning mid-infrared pulses by filamentation in gas media. Opt Lett 2012; 37: 1787\u0026ndash;89.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBaiz CR, Kubarych KJ. Ultrabroadband detection of a mid-IR continuum by chirped-pulse upconversion. Opt Lett 2011; 36: 187\u0026ndash;189.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBjorklund GC. Effects of Focusing on Third-Order Nonlinear Processes in Isotropic Media. IEEE J Quantum Electron 1975; 11: 287\u0026ndash;296.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTokmakoff A, Fayer MD, Dlott DD. Chemical Reaction Initiation and Hot-Spot Formation in Shocked Energetic Molecular Materials. J Phys Chem 1993; 97: 1901\u0026ndash;1913.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKlarskov P, Strikwerda AC, Iwaszczuk K, Jepsen PU. Experimental three-dimensional beam profiling and modeling of a terahertz beam generated from a two-color air plasma. New J Phys 2013; 15: 075012.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKnorr J, Rudolf P, Nuernberger P. A comparative study on chirped-pulse upconversion and direct multichannel MCT detection. Opt Express 2013; 21: 30693.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLee KF, Nuernberger P, Bonvalet A, Joffre M. Removing cross-phase modulation from midinfrared chirped-pulse upconversion spectra. Opt Express 2009; 17: 18738\u0026ndash;18744.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFuji T, Nomura Y. Generation of Phase-Stable Sub-Cycle Mid-Infrared Pulses from Filamentation in Nitrogen. Appl Sci 2013; 3: 122\u0026ndash;138.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFuji T, Suzuki T. Generation of sub-two-cycle mid-infrared pulses by four-wave mixing through filamentation in air. Opt Lett 2007; 32: 3330\u0026ndash;3332.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBerg\u0026eacute; L, Skupin S, K\u0026ouml;hler C, Babushkin I, Herrmann J. 3D numerical simulations of THz generation by two-color laser filaments. Phys Rev Lett 2013; 110: 073901.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBorodin A V., Panov NA, Kosareva OG, Andreeva VA, Esaulkov MN, Makarov VA \u003cem\u003eet al.\u003c/em\u003e Transformation of THz spectra emitted from dual-frequency femtosecond pulse interaction in gases. Opt Lett 2013; 38: 1906\u0026ndash;1908.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrewer SH, Franzen S. Optical properties of indium tin oxide and fluorine-doped tin oxide surfaces: correlation of reflectivity, skin depth, and plasmon frequency with conductivity. J Alloys Compd 2002; 338: 73\u0026ndash;79.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGordon IE, Rothman LS, Hill C, Kochanov R V., Tan Y, Bernath PF \u003cem\u003eet al.\u003c/em\u003e The HITRAN2016 molecular spectroscopic database. J Quant Spectrosc Radiat Transf 2017; 203: 3\u0026ndash;69.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCole-Filipiak NC, Knepper R, Wood M, Ramasesha K. Sub-picosecond to Sub-nanosecond Vibrational Energy Transfer Dynamics in Pentaerythritol Tetranitrate. J Phys Chem Lett 2020; 11: 6664\u0026ndash;6669.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYeh T-T, Shirai H, Tu C-M, Fuji T, Kobayashi T, Luo C-W. Ultrafast carrier dynamics in Ge by ultra-broadband mid-infrared probe spectroscopy. Sci Rep 2017; 7: 40492.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePravica M, Galley M, Kim E, Weck P, Liu Z. A far- and mid-infrared study of HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7- tetrazocine) under high pressure. Chem Phys Lett 2010; 500: 28\u0026ndash;34.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrechko M, Hasegawa T, Angelo FD, Ito H, Turchinovich D, Nagata Y \u003cem\u003eet al.\u003c/em\u003e Coupling between intra- and intermolecular motions in liquid water revealed by two- dimensional terahertz-infrared-visible spectroscopy. Nat Commun 2018; 9: 885.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYu CC, Chiang KY, Okuno M, Seki T, Ohto T, Yu X \u003cem\u003eet al.\u003c/em\u003e Vibrational couplings and energy transfer pathways of water\u0026rsquo;s bending mode. Nat Commun 2020; 11: 5977.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLindner J, Cringus D, Pshenichnikov MS, V\u0026ouml;hringer P. Anharmonic bend-stretch coupling in neat liquid water. Chem Phys 2007; 341: 326\u0026ndash;335.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTran H, Cunha A V., Shephard JJ, Shalit A, Hamm P, Jansen TLC \u003cem\u003eet al.\u003c/em\u003e 2D IR spectroscopy of high-pressure phases of ice. J Chem Phys 2017; 147: 144501.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu B, He C, Jin M, Ding D, Gao C. Time-resolved ultrafast carrier dynamics in CdTe quantum dots under high pressure. Phys Status Solidi Basic Res 2011; 248: 1102\u0026ndash;1105.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLu DX, Wang YH, Li FF, Huang XL, Pan LY, Gong YB \u003cem\u003eet al.\u003c/em\u003e Pressure-Dependent Relaxation Dynamics of Excitons in Conjugated Polymer Film. J Phys Chem C 2015; 119: 13194\u0026ndash;13199.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-3909502/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3909502/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMost condensed materials exhibit characteristic excitations in the far-infrared range. The ultrafast dynamics of these excitations significantly influence the fundamental physical and chemical properties of the materials. Moreover, modulating the dynamics of these excitations through pressure variations is intriguing for unveiling the key microphysical processes involved and can offer dynamic experimental support for exploring novel materials. In this study, we demonstrate the first experimental elucidation and application of ultrafast time-resolved far-infrared full-spectrum spectroscopy combined with high-pressure diamond anvil cell (DAC) technology. The combination of an air-plasmon-based continuum and an air-based single-shot upconversion detection technique have been first employed in high-pressure time-resolved infrared spectroscopy. The air-plasmon-based ultrabroadband far-infrared continuum was directed into a DAC and the transmitted pulse was detected in a single shot form through four-wave mixing in the air to avoid the absorptions from phonon modes of the nonlinear medium. It allows the real-time capture of the spectrum spanning from \u0026lt; 50 to \u0026gt; 1800 cm\u003csup\u003e− 1\u003c/sup\u003e, with a few-cm\u003csup\u003e− 1\u003c/sup\u003e spectral resolution. We investigate the pressure-dependent vibrational coupling dynamics of the complete set of vibrational fingerprint modes in microcrystalline octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) following mode-selective vibrational mode excitation. The results reveal that pressure enhances the vibrational coupling and energy transfer between the excited vibrational modes and doorway modes. The combination of high-pressure technology and time-resolved full-spectrum infrared spectroscopy opens up new perspectives for the study of the ultrafast phenomena in material science.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","manuscriptTitle":"High-Pressure Ultrafast Time-Resolved Far-Infrared Full-spectrum Spectroscopy with Air-Based Upconversion","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-02-23 04:18:04","doi":"10.21203/rs.3.rs-3909502/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"04968aee-d1c7-4fd4-9233-81f94dc30720","owner":[],"postedDate":"February 23rd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":28883945,"name":"Physical sciences/Optics and photonics/Optical techniques/Optical spectroscopy/Infrared spectroscopy"},{"id":28883946,"name":"Physical sciences/Optics and photonics/Optical physics/Supercontinuum generation"}],"tags":[],"updatedAt":"2024-04-02T05:00:33+00:00","versionOfRecord":[],"versionCreatedAt":"2024-02-23 04:18:04","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3909502","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3909502","identity":"rs-3909502","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}