Phase-resolved 2D coherent spectra of exciton-polaritons and biexcitons in a semiconductor microcavity

Monolithic semiconductor microcavities host exciton-polaritons when the exciton modes are near cavity resonance. The light-matter interactions increase and the electronic states are modified by strong coupling. Biexcitons are still present and interact with the lower polariton branch [1]. Many-body effects, such as excitation-induced dephasing and shifts, appear clearly in phase-resolved 2D coherent spectra (2DCS) in bare quantum well systems. However, to date published 2DCS in microcavity systems have examined the amplitude of the signal without the phase information. This is in part due to the strength and complexity of the optical interaction with the macroscopic sample. Here we use an experimental method that allows for capturing phase-resolved 2DCS for numerous polarization [2]. Measurements are performed on a sample containing an InGaAs quantum well as a function of the detuning between the cavity and exciton modes. Analysis of both the polariton and biexciton modes is reported.
[1] B. L. Wilmer et al, Phys. Rev. B 91, 201304(R) (2015)
[2] J. K. Wahlstrand et al, Opt. Express 27, 31790 (2019)