Appropriate use of the strength parameter in solid-state slab laser design

The manner in which the strength parameter is used in the design process for high-average-power slab lasers is examined. Fracture toughness, an intrinsic measure of the strength of brittle materials, is adopted as the appropriate parameter for comparison of different materials in a selection process. Conversely, an estimate of actual component strength is used in fixing a safe operating stress for the laser by a weibull scaling of fracture data. Measurement methods for characterizing these two strength parameters are examined for both laser glasses and crystals. Experimental results illustrating these techniques are given.