Semiconductor Diode Lasers

Abstract

This chapter deals with the technology of applying semiconductor lasers to scientific and technical fields. The use of diode lasers in technical fields is increasing because of their unique capabilities, such as tunability, high efficiency, useful power levels, reasonable coherence, and excellent modulation capabilities. The chapter focuses on the basic laser characteristics and general principles of operating single-frequency, tunable, diode laser systems. A wide variety of diode lasers is now commercially available. These range from low-power/high-speed communications lasers to high-power/wide-stripe devices, which run multimode and are used mainly for pumping solid-state lasers. For most scientific applications, it is much easier to use single spatial-mode lasers. In addition to the usual Fabry-Perot type lasers, distributed feedback (DFB) and distributed Bragg reflector (DBR) lasers are now commercially available at some wavelengths. These lasers have a more complex resonator structure that incorporates an optical grating fabricated within the semiconductor chip. Bragg reflection from the internal grating provides wavelength-selective optical feedback that forces single-longitudinal-mode operation at a wavelength within the reflection bandpass of the grating. © 1997, Academic Press, Inc.