Nearly degenerate two-color impulsive coherent Raman hyperspectral imaging

Impulsive stimulated Raman scattering (ISRS) is a robust technique for studying low frequency (< 300 cm(-1)) Raman vibrational modes, but ISRS has faced difficulty in translation to an imaging modality. A primary challenge is the separation of the pump and probe pulses. Here we introduce and demonstrate a simple strategy for ISRS spectroscopy and hyperspectral imaging that uses complementary steep edge spectral filters to separate the probe beam detection from the pump and enables simple ISRS microscopy with a single-color ultrafast laser source. ISRS spectra are obtained that span from the fingerprint region down to < 50 cm(-1) vibrational modes. Hyperspectral imaging and polarizationdependent Raman spectra are also demonstrated. (c) 2022 Optica Publishing Group

Automated summary

Impulsive stimulated Raman scattering (ISRS) is a powerful technique for studying low-frequency Raman vibrational modes, and this study introduces a simple strategy for ISRS spectroscopy and hyperspectral imaging using spectral filters.