Design criteria for concentration optimization in scaling diode end-pumped lasers to high powers: influence of thermal fracture

Abstract

A systematic investigation of a series of Nd:YVO/sub 4/ crystals with different dopant concentrations is conducted to scale the performance of diode-end-pumped lasers to higher powers. From the theoretical analysis, the fracture-limited pump power is expressed as a function of the thermal shock parameter, fractional thermal loading, and the absorption coefficient. The thermal shock parameter of Nd:YVO/sub 4/ crystals is determined from the laser experiments. Using the thermal shock parameter and the space-rate-equation model, we calculate the maximum output power in Nd:WO/sub 4/ crystals at the optimum pump condition as a function of the dopant concentration. The theoretical calculations are in good agreement with the experimental results. The influence of lowering the absorption coefficient on the TEM/sub 00/ output efficiency is also studied through the overlapping integral.