Laser amplifier

A method of highly efficient laser amplification which comprises cooling a semiconductor laser pumped, ytterbium doped YAG crystal to a temperature between 8 K and 230 K, preferably between 8 K and 100 K.

A laser amplifier which enables highly efficient laser amplification by cryogenic cooling of an ytterbium doped YAG crystal that has been pumped with a semiconductor laser having fiber output.

A method of highly efficient laser amplification which comprises cooling an ytterbium doped YAG crystal that has been pumped with a semiconductor laser to a temperature between 8 K and 230 K, preferably between 8 K and 100 K.

A laser generator comprising a semiconductor laser, fiber optics for guiding the light from the semiconductor laser, an optical system for condensing the light from the semiconductor laser as it emerges from the fiber optics, and a solid-state laser oscillator that is to be pumped with the condensed light from the semiconductor laser, wherein said laser oscillator comprises a laser amplifier composed of an ytterbium doped YAG crystal and two resonator mirrors placed on opposite sides of the laser amplifier, said crystal is cooled to between 8 K and 230 K, preferably between 8 K and 100 K, so as to reduce the optical loss in the crystal but increase the laser gain, thereby producing synergism to enhance the laser amplifying performance of the crystal.