Simple configurations for hybrid coherent Raman microspectroscopy

Abstract

Hybrid coherent Raman spectroscopy, which combines synchronized broadband pumping and time-delayed narrowband probing with frequency-resolved detection, is able to achieve fast spectroscopic detection and to eliminate problematic nonresonant background. In this technique, abundant characteristic vibrations and rotations of molecules are excited and detected simultaneously in a single shot without wavelength scanning, so real-time spectroscopic detecting is possible. Besides, a narrowband probing results in distinguishingly resonant peaks standing out against a flat nonresonant background spectrum in frequency domain. Furthermore, separating excitation and probe pulses in time suppresses the nonresonant background due to different temporal characteristics between a Raman-resonant signal and nonresonant backgrounds.