A solid state laser comprises a laser element formed from crystalline, ceramic, glass ceramic, glass, or plastic material in the configuration of a rod or slab. The cooling capabilities of the rods or slabs are improved by the provision of internal bores or slots through which a coolant can flow, and/or...http://www.google.de/patents/US4845721?utm_source=gb-gplus-sharePatent US4845721 - Solid state laser rods for high power conditions
