Detecting THz signatures of liquids with chirp induced stimulated Raman scattering

We present an experimental scheme enabling us to excite and detect THz Raman modes of liquids. In doing so, we overlap two chirped laser pulses at the liquid sample to induce stimulated Raman scattering (SRS). Thereby, the delay time between these pulses is directly related to the frequency of the molecular excitation. In consequence of the non-linear SRS process, we can detect an energy transfer between the two pulses. With the presented experimental scheme, we have access to a broad frequency range spanning two orders of magnitude between ultra-low frequencies at 100 GHz up to 10 THz.