Abstract
We propose cooperative two-photon lasing in two quantum dots coupled to a single mode photonic crystal cavity. We consider both quantum dots are driven either incoherently or coherently using external pump. We incorporate exciton-phonon coupling using polaron transformed master equation. Using quantum laser theory, single and multi-photon excess emission (difference between emission and absorption) into cavity mode are investigated. The single and two-photon excess emission contribute to cavity photons, predominantly. Varying the pump strength can lead to single-photon excess emission change from negative to positive and thus by appropriately selecting pump strength single-photon excess emission can be made negligible.