We study a system of interacting excitons strongly coupled to photons inside an optomechanical microcavity. The presence of the mechanical mode leads to an interactive type of optomechanical coupling, which is different from the dispersive and dissipative couplings in optomechanical systems. This interactive coupling is shown to generate effective optical nonlinearity terms of high order (quadratic in polariton number), which is responsible for the appearance of bright flat-top solitons in polariton condensate.
Read more at Phys. Rev. B 95, 085309 (2017)