Exciton reservoir-induced destabilization and reformation of polariton condensate

We investigate the dynamics of a driven-dissipative polariton condensate in a GaAs microcavity under simultaneous excitations by a continuous laser and a pulsed laser. The femtosecond pulse destabilizes and quenches the condensate, which is then followed by a nonlinear luminescence surplus. Time-resolved photoluminescence shows a ring-like pattern in momentum space that shrinks as the condensate relaxes back to its steady state. The condensate also experiences an abrupt blueshift in energy after the pulse before returning to equilibrium. Simulations based on the driven-dissipative Gross-Pitaevskii equation confirm the importance of interactions between exciton reservoir and polaritons. This study clarifies how reservoir-mediated interactions shape the nonlinear processes underlying polariton condensation.