Measurement of minority carrier lifetime during gradual degradation of GaAs-Ga1-xAlxAs double- heterostructure lasers

Minority carrier lifetime in the active layer of GaAs-Ga1-x- AlxAs double-heterostructure lasers has been found to decrease during gradual degradation by measuring the lasing delay time. This phenomenon is ascribed to a decrease in the internal quantum efficiency. Furthermore, a development of the inhomogeneity in the active layer is deduced from observations of the change of near-field patterns, light intensity versus current characteristics, and photoluminescence patterns.