Polarization dependence of chirp-induced nonlinear Raman scattering spectroscopy of aqueous ions and organic liquids in the THz regime

We present polarization dependent measurements of coherent Raman spectra of liquids with chirped ps-pulses in the THz regime. In order to detect the coherent Raman spectrum we made use of a, previously introduced [1, 2], nonlinear pump and probe scheme involving an experimental technique called “spectral focusing”. As a result, we are able to resolve spectrally stimulated Raman gain and inverse Raman scattering. Our experiment covers the entire THz range from 10 THz down to 100 GHz. Thereby, we show that different spectral features of aqueous ions and organic liquids can be distinguished using different polarization states of the pump beam.