Abstract

A critical problem facing the application of simple monolithic semiconductor lasers in coherent lightwave systems is the effect of optical feedback on the spectra of these lasers.¹ It has been observed that feedback levels as small as -80 dB can significantly narrow or broaden the laser linewidth. Lasers operating cw exhibit a rich variety of feedback effects, which can be categorized into five distinct regimes, depending on the feedback level and the distance to the reflection²:

© 1988 Optical Society of America