Intrinsic optical heterodyne detection of a two-dimensional fifth order Raman response

Intrinsic optical heterodyne detection is applied to femtosecond two-dimensional (2-D) vibrational spectroscopy of the Raman active inter- and intramolecular modes of liquid CS2 between 1 and 1000 cm−1. Heterodyne detection is accomplished with a novel wave vector matching geometry that allows detection of the cross term between the third and fifth order response, R(3)R(5). The increase in the bandwidth and sensitivity through this detection technique will allow the measurement of 2-D temporal or spectral responses for a wide variety of systems in this frequency range.