Strip laser amplifier and laser output method thereof

The invention discloses a strip laser amplifier and a laser output method of the strip laser amplifier. The strip laser amplifier comprises a seed laser module, a pumping module, a gain medium module and a dichroic mirror module, wherein the pumping module, the dichroic mirror module and the gain medium module are arranged side by side, and the seed laser module is arranged on one side of the module parallel with the seed laser module. The strip laser amplifier further comprises a reflector module. The gain medium module comprises a laser crystal and two cooling heat sinks, the laser crystal is formed by bonding a doped laser crystal and two non-doped laser crystals without adhesives, and the thickness of the laser crystal is 0.5-1.5 mm. The bonded laser crystal of an ultrathin strip structure serves as a gain medium of the laser amplifier, the reflector module is used to realize double-stroke amplification, the heat effect of the laser crystal is reduced, the surface damage threshold value of the laser crystal is reinforced, the laser gain extraction efficiency is increased, and continuous or pulse laser amplification output with high output power and high light beam quality can be obtained.