A review of diode-pumped lasers: advances in lasers and applications

Hanna, D.C. and Clarkson, W.A. (1998) A review of diode-pumped lasers: advances in lasers and applications. 52nd Scottish Universities Summer School in Physics (SUSSP-52), St Andrews, United Kingdom. 05 - 13 Sep 1998.

Abstract

The first demonstration of a diode-pumped laser was in 1964 (Keyes and Quist 1964), just two years after the first operation of a diode laser. Potential attractions of diode pumping, compared with pumping by an incandescent lamp, were evident at that time. However, it needed about 20 years before diode lasers became commercially available with long life under room-temperature operating conditions and with the power levels appropriate for laser pumping. Pioneering experiments performed using such diode lasers as pumps graphically illustrated the benefits of diode-pumping and were discussed in an early review paper (Byer 1988). These benefits include high efficiency, compactness, stable low-noise operation, reduced thermal effects in the laser medium, long-life and the prospect, if not an immediate benefit, of low cost. Decreasing costs of diode lasers and increasing diode powers have gone hand-in-hand and so fuelled this interest in diode pumped lasers. As these trends continue, so there is an inexorable move towards diode-pumped lasers of ever greater power. The earlier prevailing notion that diode-pumped lasers are free from pump-induced thermal effects, has long gone. That was, to some extent, a consequence of the low diode powers initially available. Now, with diode lasers offering tens of Watts of pump power, thermal problems have become a key issue in the further development of diode-pumped lasers. This question of thermal problems will form an important theme of this brief tutorial review (Section 3). First however (in Section 2), we will briefly consider the question of appropriate geometries (pumping configuration, shape of laser medium, resonator geometry) for diode-pumped solid-state lasers. In fact there is now a bewildering variety of geometries under investigation, with many being commercially available, each with its staunch champions. Clearly the optimum choice of geometry is far from being a settled question. In fact, it is interesting to note that two of the currently favoured geometries, namely the fibre laser and the face-pumped thin disc laser, represent two diametrically opposed extremes from a basic cylindrical rod geometry. With such widely divergent approaches, it is clear that there is still considerable scope for innovative ideas in this area and even relatively small changes in, for example, the available brightness or power of diode lasers, could have major consequences in terms of changing the balance between favoured geometries, or indeed, stimulating the invention of yet more contenders.

This record has no associated files available for download.

Contributors

Download statistics