Efficient, phase-resolved polarization-dependent two-dimensional coherent spectroscopy

Capturing spectra for multiple polarization configurations in two-dimensional coherent spectroscopy allows access to different quantum pathways in the light-matter interactions probed by the technique. This is typically done by manually rotating waveplates. We demonstrate a liquid crystal variable retarder-based control scheme to efficiently capture common polarization configurations of the rephasing four-wave mixing of a semiconductor microcavity, showing that the presence of biexcitons alters the nonlinear response of the exciton polaritons. We find the proper phase of the complex 2D spectrum for the collinear polarization configuration in the usual way, by comparing the four-wave mixing emission to the spectrally-resolved transient absorption. Importantly, because the phase shift induced by the variable retarders is known, spectra for all other polarization configurations can be correctly phased.