Chapter 4 - High-Power Semiconductor Lasers

Abstract

This chapter discusses the issues that determine the beam quality and power output of high-power semiconductor lasers. An important class of applications requires much higher powers either in pulsed or continuous-wave (c.w.) operation. Operation in a single spatial mode or on a single frequency line is often desirable, but not necessarily a requirement. This chapter reviews the framework for the analysis and design of high-power semiconductor lasers. These lasers have a variety of applications within the commercial and scientific marketplace, and the utility of semiconductor lasers lies within their wavelength span from the visible spectrum to the mid-infrared. High-power lasers are demanded by applications where the light is not acting as a passive probe but an active workhorse to pump lasers and amplifiers, activate photodynamic drugs, or act as laser tweezers and scissors. The issues discussed in this chapter (power limitations, beam quality, and thermal management) are common to all semiconductor laser materials. As these issues have come to be understood more fully in the past several years, great advances in reliable output power have resulted, enabling semiconductor lasers to replace bulkier and less efficient gas and solid-state lasers, as well as opening up new applications. As new material systems mature, the future of semiconductor lasers continues to look bright.