Solid-state lasers pumped by advanced diode laser sources

Abstract

Diode laser sources are inherently continuous-wave devices because their output is peak-power limited. Thus, for average power performance, more effective use of the pump diode lasers is obtained in high-repetition- rate, as opposed to low-repetition-rate, operation; the latter requires more diode to achieve a given average power. I report on a Nd:YAG laser pumped by high repetitionrate, two-dimensional arrays and on the use of a strained layer in InGaAs quantum-well diode lasers as pump sources for solid-state lasers. Two-dimensional rack-and-stack arrays have been limited to relatively low repetition rates and low duty cycles because of difficulties in heat removal; planar geometries cooled by microchannel heat sinks allow higher duty cycles. Average output power of 11 W from a Nd:YAG slab laser has been demonstrated with no evidence of adverse thermal effects in the pump lasers. The development of strain-layer InGaAs diode lasers opens new possibilities for diode-pumped lasers; the main application of these diode lasers has been for pumping Er3+ fiber amplifiers. The use of these diode lasers to pump bulk lasers such as Nd3+, Yb3+, and Er3+ will be discussed.