Towards single shot multidimensional terahertz spectroscopy of hydrogen-bonded liquids

Abstract

Two-dimensional terahertz-terahertz-Raman (TTR) spectroscopy provides a direct probe of low energy, thermally excited intra- and inter-mol. modes of liqs. at room temp., as well as information on the modes' anharmonicities. However, the need to use two delay stages to sample the TTR response results in datasets that take tens of hours to acquire, thus limiting our ability to explore chem. and thermodn. space. To combat this difficulty, we present a single shot TTR spectrometer which, by replacing one delay line with a reflective echelon, allows tens of picoseconds of mol. dynamics to be captured in milliseconds, as opposed to the minutes previosuly required. We present a series of TTR results on room temp. liqs. highlighting the capabilities of the instrument and areas for improvement.