We describe a technique for the quick and simple assessment of doped optical materials for use as laser gain media. To demonstrate this technique, referred to as Rapid Thermo-Optical Assessment (RTOA), we analyze a set of ceramic and crystalline Yb3+:YAG samples. RTOA is based on Shack-Hartmann wavefront sensing and thermal lensing to evaluate the media\u27s thermal response, giving a relative overall quality assessment of the material. The technique is also broadly applicable to optical media considered for high power or thermal loading conditions, and useful for the refinement of fabrication methods
