Nonlinear gain compression in tensile-strained 1.5-μm single quantum well lasers

The origin of gain compression in quantum well (QW) lasen is a subject of recent interest in laser dynamics. In particular, the question of whether the magnitude of gain compression scales with differential gain (dgldn), even for devices of different structure and operating in different conditions, is an important one. In this paper, we study the dependence of the magnitude of gain compression coefficient on differential gain using 1.5-μm tensile-strained QW lasers with different cavity lengths and facet coatings. Our results indicate a strong direct correlation between gain compression coefficient and differential gain, even for devices lasing in different subbands. The reservoir model proposed recently1 fits this experimental observation, although the nature of the gain compression is still unclear.