Abstract

The recent development of semiconductor laser diode arrays producing high average power (CW or near-unity pulsed duty factors) at high efficiency is enabling the design, development, and commercialization of high average power diode-pumped solid state lasers (DPSSLs) with excellent output beam quality. The compactness, high reliability, and radiation-delivery-by-fiber achievable with high-brightness DPSSLs has prompted interest by a wide variety of application users. Although near resonant pumping with narrowband diode pump arrays reduces specific thermal loadings of typical laser gain media by factors of several-fold compared to flashlamp pumping, the realization of high average power DPSSLs (tens of watts to kilowatts) requires the development and implementation of novel laser architectures, laser cavity resonators, gain element geometries, and pump array coupling optics. For applications requiring complex temporal output waveofrms, the development and functional integration of high average power Q-switches and non-linear frequency shifters will be necessary. This tutorial will review the above mentioned design considerations for several types of high average power DPSSLs in relation to the spectroscopic, optical, thermal, and mechanical characteristics of relevant solid state laser gain media. A summary of the present state of performance of di ode pump arrays will also be given along with a survey of the performance levels presently attained by high average power DPSSLs. A brief forcast of future development in high average power DPSSLs will be given.

© 1995 IEEE