Tunable femtosecond optical parametric amplifier pumped by 1 kHz ultrafast thin-disk laser pulses for coherent anti-Stokes Raman scattering

Abstract

Coherent anti-Stokes Raman spectroscopy (CARS) is a powerful tool in combustion diagnostics [1] . It requires three beams, the pump, Stokes and probe beam with at least two different wavelengths. For high pressure applications, the use of fs-pulses is of additional benefit, as the CARS signal is free from distortions from molecular collisions, if the excited Raman level is probed within a few ps [2] . On the other hand, too short pulses (~100-500 fs) result in poor spectral resolution [3] . In this study, we present an optical parametric amplifier (OPA), providing a maximum pulse energy of ~200 µJ, at 700-900 nm and a pulse duration of ~1 ps. Using a pump source at 1030 nm, this setup may serve as a customized fs-CARS system for high pressure gas analysis.