Abstract

The temperature sensitivity of long wavelength (1.5µm) semiconductor lasers, denoted by the characteristic temperature, T_o, has remained poor, with T_o values typically ranging from 40K up to a maximum of order 100K. There still remains controversy as to the cause of this temperature sensitivity. Several groups have suggested that the problem is due to the differential gain decreasing rapidly with increasing temperature [1-2], or is due to the temperature dependence of a strong stimulated emission component below threshold [3], However, this work has involved lasers with low T_o values, of order 40K, and so it has not yet been convincingly demonstrated as to what is the limiting mechanism for lasers with higher T_o values. We have provided direct evidence in a previous paper that the radiative component of the threshold current is perfectly well behaved in 1.5µm strained and unstrained quantum well lasers, with a characteristic temperature, T_o, close to 300K at room temperature

© 1996 Optical Society of America