Abstract:
A new lasing mechanism for semiconductors like CuCl, CuBr is proposed based on the two-photon pumping of biexcitons from the ground state of the crystal and generation or amplification of light in the region of M-band of luminescence due to the optical exciton-biexciton conversion. It was shown that the net gain essentially depends on the level of two-photon pumping and rapidly decreases deep into the crystal due to the spatial depletion of pump radiation.