[24p-D315-1~11] 3.6 Ultrashort-pulse and high-intensity lasers

▼ [24p-D315-2] Interferometer-Based Background-Free Vibrational Spectroscopy
using a Cr: ZnS Mode-Locked Laser

〇(D)WENQING SONG¹, OKAZAKI DAIKI¹, MORICHIKA IKKI¹, ASHIHARA SATOSHI¹ (1.IIS, The Univ. of Tokyo)

Keywords:Cr: ZnS laser, Vibrational spectroscopy

In this study, we demonstrate a highly sensitive background-free vibrational spectroscopy (BFS) using a well-stabilized interferometer and a Cr:ZnS mode-locked femtosecond laser, which provides high brightness, broadband spectrum in the mid infrared range with low intensity noise. The free-induction decay spectrum of methane and carbon monoxide around 2.3 um is shown. And based on the noise analysis, we calculate the theoretical limit of detection (LOD) of our system. Finally, a validation experiment targeting the ro-vibrational transition lines of R-branch for carbon monoxide confirms the LOD to be 6.32×10^-6 (Hz^-1/2).