Abstract

A passive and lens-free alignment between a laser diode and a single-mode fiber is a promising way to realize low-cost subscriber laser modules. An integrated laser with a spot-size transformer^1-4 is supposed to be a key device to provide large alignment tolerances and superior coupling efficiency to an optical fiber. Recently, we reported the integration of a tapered thickness spot-size transformer to a 1.3-μm multiple quantum well (MQW) laser diode, confirming a sufficient coupling performance with superior lasing characteristics over a wide temperature range. However, when the coupling efficiency of a laser to a fiber increases, influence of the optical feedback light could also increase. In this paper we report on modulation characteristics of the tapered thickness waveguide BH MQW lasers with external optical feedback.

© 1996 Optical Society of America