Abstract

Nonlinear effects such as gain suppression and spatial hole burning, dramtically affect the output characteristics of phase-shifted distributed-feedback (DFB) lasers. An understanding of the different physical phenomena involved in the nonlinear effects would help in the design of high-performance devices. Many of theoretical studies have reported on this subject, showing, in particular, that carrier heating is expected to be the main cause of nonlinear gain in strained multiple-quantum-well (MQW) lasers.¹ This paper reports experimental evidence of nonlinear gain and spatial hole burning in bulk and strained MQW phase-shifted DFB lasers through spectral and spatial observation of spontaneous emission.

© 1995 Optical Society of America