Time-Domain Coherent Anti-Stokes Raman Scattering Signal Detection for THz Vibrational Spectroscopy Using Chirped Femtosecond-Pulses

摘要

A new scheme for low-frequency coherent anti-Stokes Raman scattering (CARS) spectroscopy using chirped femtosecond pulses is proposed and demonstrated. Two chirped broadband optical pulses created terahertz (THz) polarization in the sample and generated CARS signal. The chirped CARS signal was compressed and detected in time-domain by using sum frequency generation. A resonant Raman band of GaSe at around 0.6 THz was successfully detected with the time-domain CARS system. With the present system CARS spectra from 0.2 to 5 THz is obtainable.