Effective Rabi frequency in ultrafast semiconductor lasers: self-starting harmonic frequency combs

Effective Rabi frequency in ultrafast semiconductor lasers: self-starting harmonic frequency combs | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Effective Rabi frequency in ultrafast semiconductor lasers: self-starting harmonic frequency combs Lorenzo Luigi Columbo, Carlo Silvestri, Franco Prati, Massimno Brambilla, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7643429/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 12 You are reading this latest preprint version Abstract Optical frequency combs have become a key research topic in optics and photonics. A peculiar comb state is the harmonic frequency comb (HFC), where optical lines are spaced by integer multiples of the cavity’s free-spectral range. The spontaneous formation of HFCs has recently been observed in semiconductor lasers with fast gain recovery, such as Quantum Cascade Lasers (QCLs), although the underlying physical mechanism remains unclear. In this work, we provide a physical interpretation for the formation of HFCs in QCLs, based on a resonance phenomenon between an effective Rabi frequency and a mode of the laser cavity. This is corroborated by the results of the numerical integration of the effective semiconductor Maxwell-Bloch equations used to describe the multimode laser dynamics, as well as by the linear stability analysis of the continuous wave emission at threshold. Physical sciences/Optics and photonics/Lasers, LEDs and light sources/Quantum cascade lasers Physical sciences/Optics and photonics/Lasers, LEDs and light sources/Semiconductor lasers Full Text Additional Declarations There is no conflict of interest Supplementary Files Supplementaryinfo.pdf Effective Rabi frequency in ultrafast semiconductor lasers: self-starting harmonic frequency combs – Supplementary materials Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: revise 02 Dec, 2025 Review # 3 received at journal 24 Nov, 2025 Review # 4 received at journal 10 Nov, 2025 Reviewer # 4 agreed at journal 24 Oct, 2025 Review # 1 received at journal 20 Oct, 2025 Reviewer # 3 agreed at journal 29 Sep, 2025 Reviewer # 2 agreed at journal 27 Sep, 2025 Reviewer # 1 agreed at journal 23 Sep, 2025 Reviewers invited by journal 23 Sep, 2025 Submission checks completed at journal 23 Sep, 2025 Editor assigned by journal 17 Sep, 2025 First submitted to journal 17 Sep, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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