Single Mode Metal-Insulator-Semiconductor Heterostructure Lasers

Abstract

Metal-Insulator-Semiconductor (MIS) injection lasers having various structural configurations are discussed for single mode operation in the wavelength range of 0.72-1.55 microns. MIS interfaces are used as an alternative to p-n heterojunctions to obtain effective minority carrier injection and subsequent lasing action in the active layer. Emitted photons are confined in the active layer as they are reflected by a heterostructure dielectric discontinuity on one side and perfectly reflecting surface of the barrier metal on the other side. Modal analysis of a stripe geometry MIS laser involving both lateral and transverse modes is presented. A comparison of the output characteristics, highlighting the differences in transverse modal behavior of MIS laser structures with a conventional p-n double heterostructure (DH) lasers, operating at the same wavelength, is reported. A novel distributed feedback (DFB) laser employing an MIS heterostructure, rather than a p-n heterojunction, is also proposed. The simplicity of fabrication of the proposed DFB laser lends itself to monolithic integration with optical waveguides and other electronic and optoelectronic devices.