Tilted valance-band quantum well double heterostructures for single step

Abstract

Opto-electronic integrated waveguide devices are provided using a tilted valence band quantum well semiconductor double heterostructure with one growth of the same waveguide material, that operate simply by their normal operating forward bias for active waveguides with optical gain and operating in a reverse or no bias for active waveguide without optical gain or passive waveguides. The optical waveguides comprise a substrate, a bottom cladding layer, a core layer having a quantum well optical waveguiding double heterostructure and a top cladding layer. The quantum well optical waveguiding double heterostructure includes an InGaPAs first barrier layer atop the bottom cladding layer, a quantum well layer constructed of InxGa1.sub.-x-y Al.sub.y As is stacked on top of the first barrier layer which is graded from one side to the other forming a linearly increasing quantum well energy bandgap and an In.sub..52 AlGaAs second barrier layer is stacked on top of said quantum well core layer. The quantum well layer provides a first conduction band offset ratio at a first interface point smaller than a second conduction band offset ratio at a second interface point, as well as a valence band being tilted, with the first barrier layer energy bandgap being greater than the quantum well energy bandgap, and the quantum well energy bandgap being lesser than said second barrier layer energy bandgap. The first barrier layer, quantum well layer and second barrier layer can be coextensive with one another.