Multiplex Raman induced Kerr effect microscopy.
We report spectrally-resolved chemical imaging based on Raman induced Kerr effect spectroscopy (RIKES). When used with circularly-polarized pump excitation, multiplex RIKES offers the potential for spectrally-resolved imaging free of the nonresonant background that plagues coherent anti-Stokes Raman scattering. RIKES does however have a highly sample-dependent birefringent background that limits its sensitivity and can introduce spectral distortions. We demonstrate that in low birefringence samples multiplex RIKES microscopy offers an enhanced signal-to-noise ratio compared to multiplex stimulated Raman scattering (SRS) when implemented in a high polarization-purity, low frequency chopping scheme.