ANALYSIS OF GAIN IN DETERMINING T-0 IN 1.3 MU-M SEMICONDUCTOR-LASERS

Rapid decrease of differential gain has been determined to dominate the temperature dependence of threshold current in 1.3-mu m multiquantum well and bulk active lasers giving rise to low values of T-0, Extensive experimental characterization of each type of device is described, Results are presented for the dependence of gain on chemical potential and carrier density as a function of temperature, The data indicate the important role of the temperature-insensitive, carrier density dependent chemical potential in determining differential gain, Modeling of the temperature dependence of threshold carrier density in MQW and bulk active lasers based on a detailed band theory calculation is described, The calculated value of T-0 depends on the structure of the active layer, e,g., multiquantum well versus bulk, However, the calculated values are substantially higher than measured.