Dynamic and sensitive hybrid fs/ps vibrational CARS thermometry using a quasi-common-path second-harmonic bandwidth-compressed probe

Abstract

We demonstrate a 1-kHz, single-shot, dynamic, and sensitive flame temperature measurement using hybrid femtosecond/picosecond vibrational coherent anti-Stokes Raman scattering. This benefits from a 7-cm-1, 240-μJ, and sideband-free picosecond pulse out of a broadband 35-fs pulse through a quasi-common-path second harmonic bandwidth compressor system. Measurements around optimal time delay exhibit superior performance with a temperature inaccuracy of less than 1% and a precision of ∼2% at 1790 K. These results demonstrate the advantages and potential for the accurate and fast temperature measurement in practical or harsh environments.