Evaluation of carrier density and gain profile in semiconductor laser

In this paper, a precise method for computing the optical gain/loss in an optically pumped semiconductor material is reported. Variations of the gain coefficient, as a function of pump light frequency for different band gap energies, temperature and carrier densities, are described. In another study, variations of the electron and hole densities are simulated and the resulting integrals are evaluated numerically. The changes of carrier density in an intrinsic GaAs semiconductor as a function of the position of the Quasi-Fermi levels in the conduction or valence bands for different temperatures, are also reported. For GaAs laser, accurate normalized densities are obtained as a function of temperature. The normalized densities at T = 300degK are at the ratio of 1.98:1:0.4 for T = 200, 300 and 400degK, respectively. The peak gain values, normalized at the same room temperature, are at the ratio of 2.05:1:0.36, for T=200,300 and 400degK, respectively. Comparing the results presented for the carrier density and gain, with other studies, this method provides an accurate result. It is noted that temperature has a dominating effect on the gain profile and, as a result, on the laser overall performance as observed in the experiments