Photonic-crystal laser mediated by polaritons

A polariton-mediated photonic-crystal laser is proposed, which has a periodic structure containing excitonic and gain materials in its unit cell. This type of structure is shown to significantly intensify optical gain near the polaritonic band edge as a result of using a light, the band of which is split into small polaritonic bands by exciton-photon coupling. Consequently, this laser exhibits much lower threshold gain than those of other lasers studied here and it oscillates in the single mode because of its strong mode selectivity. These advantages stem from the photon field modulated extremely by adding excitons to conventional photonic crystals.