Polarization-controlled amplified spontaneous emission in 2D semiconductors with birefringent microcavity

We report on the polarization-controlled amplification of excitonic emission in the monolayer WS₂ coupled with ZnO microcavity. From polarization-resolved micro-photoluminescence spectroscopy and numerical modeling, we found that the polarization of WS₂ excitonic emission can be tailored by the whispering gallery modes of the birefringent ZnO microcavity. Furthermore, the light input-light output curves exhibit the clear threshold kink and the superlinear increase in the output intensity for both the TM and TE polarization modes, indicating the polarization-dependent amplification of excitonic emission. Our results suggest an approach to realize the polarization-controlled photonic devices based on 2D materials.