CALCULATION AND ANALYSIS FOR LIGHT AMPLIFICATION WITHOUT INVERSION INA SEMICONDUCTOR QUANTUM-WELL

In the presence of a coherent coupling between intersubbands of the co nduction band in a semiconductor quantum well, light amplification wit hout inversion is investigated by solving the density matrix equation and analyzed by the electron renormalization theory. The quasi-Fermi e nergy level is used to take the place of injection rate. This shows th at the amplification of the interband transition without population in version in the bare state can emerge on the lower frequency side of th e resonant transition only. This result could be understood as populat ion inversion in the dressed state representation.