Gallium Arsenide-Gallium Aluminum Arsenide Distributed Feedback and Distributed Bragg Reflector Lasers

This work describes theoretical and experimental studies of GaAs/GaAlAs distributed feedback and distributed Bragg reflector lasers. These lasers are strong candidates as the light source in integrated optical circuits and optical communication systems. A coupled-mode formalism is used to study the propagation of electromagnetic waves in a dielectric waveguide with periodic surface corrugation. The reflection and transmission characteristics of both passive and active periodic waveguides are found as a function of wavelength. These results are used to derive the oscillation conditions of two different laser structures: (1) the distributed feedback laser - where a corrugated active waveguide section is the basic structure, (2) the distributed Bragg reflector laser - where an active region is flanked by two sections of passive periodic waveguides. The procedure of determining the lasing wavelength is outlined. The merits and disadvantages of various laser structures are compared and discussed. Experimental results on fabrication and measurements of GaAs/GaAlAs distributed feedback and distributed Bragg reflector lasers are presented and compared with the theory. Various fabrication and measurement techniques developed during the course of the investigation are described in some detail.