Exploring the lateral degree of freedom semiconductor lasers

Abstract

Ease of integration is only one of the great potential of the lateral injection lasers which results from the release of an additional degree of freedom. For example, the use of non-conducting cladding layers enables capacitive modulation and gain and/or wavelength tuning from a top electrode. Post-fabrication processing via deposition and modification of dielectric on a base structure allows us to add and extract different functionalities, which too is enabled by the absence of vertical injection through the layers. The use of the lateral degree of freedom reduces or removes the need for compromises between the electrical and optical design considerations which exist in the vertical paradigm. One benefit of this decoupling between the electrical and optical designs is that large bandgap undoped materials can be used in cladding and barrier layers to enhance both optical and electrical confinements without inducing extra resistance, heat and carrier non-uniformity and with reduced chirping.