Abstract

An important problem in using the GaAs/GaAlAs heterostructure system for integrated optics is that of transferring the guided wave in the active region of the laser into a wider bandgap transparent waveguide. Although several types of taper couplers¹,² and twin guide couplers³ have been demonstrated, these have generally been difficult to fabricate. In this paper we describe the fabrication and operation of a new branching directional coupler, which can be readily grown by conventional liquid phase epitaxy (LPE). Although our device is used herein to provide a multi-mirror laser cavity which, because of interference effects, improves laser longitudinal mode structure, we believe it to be suitable for other integrated optical configurations.

© 1978 Optical Society of America