High-speed full-field entire bandwidth mid-infrared chemical imaging

Abstract Mid-infrared spectroscopy probes molecular vibrations to identify chemical species and functional groups. Therefore, mid-infrared hyperspectral imaging is one of the most powerful and promising candidates for chemical imaging using optical methods. Yet high-speed and entire bandwidth mid-infrared hyperspectral imaging has not been realized. Here we report a mid-infrared hyperspectral chemical imaging technique using chirped pulse upconversion of sub-half-cycle pulses at the image plane, that the lateral resolution is 15 μm, and the field of view is adjustable between 800 μm × 600 μm to 12 mm × 9 mm. A 640 × 480 pixel image can be obtained in 8 s at the hyperspectral imaging, which comprises 1069 wavelength points and covers a spectral range of 640–3015 cm–1 with a wavenumber resolution of 2.6–3.7 cm–1. For discrete frequency mid-infrared imaging, the measurement speed reaches a frame rate of 5 kHz, the repetition rate of the laser. As a demonstration, we effectively identified and mapped different components in a microfluidic device, plant cell, and mouse embryo section. The great capacity and latent force of this technique in chemical imaging promise to be applied to many fields such as chemical analysis, biology, and medicine.