2022/10/13 by Sergey Vasilyev, Vasilyev, Sergey, Andrey Muraviev +13
Chemistry · Engineering · Physics and Astronomy · #Advanced Fiber Laser Technologies #Applied Physics (physics.app-ph) #FOS: Physical sciences #Optics (physics.optics) #Photonic and Optical Devices #Spectroscopy and Laser Applications
paper · pdf · doi:10.48550/arxiv.2210.07421
openalex publication_date 2022/10/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report molecular detection using dual frequency-comb spectroscopy with highly coherent broadband (6.6-11.4 \mm) long-wavelength infrared (LWIR) combs. The combs were produced via intra-pulse difference frequency generation (IDFG) in ZGP crystals using sub-three-cycle (20 fs) driving pulses from mode-locked Cr:ZnS lasers at the central wavelength of 2.4 \mm). Real-time and up to video rate (0.1-12 s per spectrum) acquisition of molecular spectra with some 240,000 comb-mode-resolved data points spaced by 80 MHz and referenced to a Rb clock with a signal-to-noise ratio (SNR) >300 has been demonstrated. The key to achieving such a high rate of massive spectral data acquisition is a low phase and intensity noise of the LWIR combs and excellent mutual coherence. The high SNR was also facilitated by the high (7.5%) IDFG conversion efficiency resulting in an average LWIR comb power of 300 mW per channel.