  Exciton-polaritons in semiconductor microcavities generate fascinating
effects such as long-range spatial coherence and Bose-Einstein Condensation
(BEC), which are attractive for their potential use in low threshold lasers,
vortices and slowing light, etc. However, currently most of exciton-polariton
effects either occur at cryogenic temperature or rely on expensive cavity
fabrication procedures. Further exploring new semiconductor microcavities with
stronger exciton photon interaction strength is extensively needed. Herein, we
demonstrate room temperature photon exciton strong coupling in hybrid
inorganic-organic CH3NH3PbBr3 Fabry-P\'erot microcavities for the first time.
The vacuum Rabi splitting energy is up to ~390 meV, which is ascribed to large
oscillator strength and photon confinement in reduced dimension of optical
microcavities. With increasing pumping energy, exciton-photon coupling strength
is weakened due to carrier screening effect, leading to occurrence of photonic
lasing instead of polartion lasing. The demonstrated strong coupling between
photons and excitons in perovskite microcavities would be helpful for
development of high performance polariton-based incoherent and coherent light
sources, nonlinear optics, and slow light applications.
