Exciton-polariton lasing with polarization fixing reciprocal space resolved at room temperature

Exciton-polaritons are quasiparticles that are defined by the interaction between semiconductors and optical cavities. The ultra-low effective mass of polariton quasi-particles from its photonic component facilitates the polariton lasing processes at high temperature. The fixing of initial exciton polarization necessitates a method to achieve a stable polarized output. In this paper, we demonstrate the polarization-fixed polariton condensation lasing at room temperature, which is based on the anisotropy inherent in the gain media crystal structure. At the threshold (Pth = 25 kW cm−2), emission intensity exhibits nonlinear growth, and linewidth undergoes a sharp contraction. The dispersion curve of TE–TM polarization splitting was fitted by using a coupled Lorentz resonator model. Its validity was verified by adjusting the detuning amount to match experimental results. Moreover, the perpendicular emission directions of TE and TM polarization are indicated by reciprocal space imaging. The significance of first-order coherence of polariton lasing is explained qualitatively via the Michelson interferometer. Our results provide a feasible route for the development of polariton optoelectronic devices with tunable polarization degrees of freedom.