Abstract: In a high power laser the optical resonator elements, such as reflectors for the optical resonator and optical pump are supported in optical alignment from a structural beam of generally L-shaped cross section and made of high thermal conductivity material such as copper or aluminum via the intermediary of a plurality of longitudinally directed rods made of a low thermal expansion material such as quartz or Invar. The rods are supported at one end from the L-shaped beam via leaf springs and they are rigidly coupled to the L-shaped beam at their other ends. The remaining elements such as the optical pump, Q switch and polarizers are supported directly from the L-shaped structural beam.

Abstract: In an optically pumped high power laser the optical pump includes a housing containing a pair of flash lamps and an elliptical reflector assembly for reflecting the optical pumping radiation into the laser gain medium, such as a YAG rod. Water coolant is directed through the housing in contacting relation with the YAG rod and flash lamps. An ultraviolet band reject filter, comprising a split cylindrical sleeve, is disposed surrounding the laser gain medium in between the laser gain medium and the flash lamps and in contact with the water coolant.

Abstract: A crystal growing furnace is provided wherein the molten material in the crucible is replaced constantly as it is withdrawn by a monitoring system which automatically maintains the level in the crucible at a desired point. A replaceable cannister system is also provided so that the level can be maintained indefinitely by replacing the cannisters.