Injection-seeded Q-switched laser based on a double corner cube retroreflector ring cavity

An injection-seeded Q-switched Er:YAGlaser with a double-corner-cube-retroreflector (DCCR) ring cavity has been demonstrated for the first time. The output coupling tuning range of the DCCR ring cavity was calculated to be 2.4% ∼ 97.5%. By tuning the output coupling, the injection-seeded Q-switched Er:YAG laser outputs a 1645 nm single-frequency laser pulse with optimum efficiency at pump powers of 23.2, 24.2, 25.2, and 26.2 W. The corresponding measured output coupling ratios are 1.6, 2.4, 2.4, and 2.4%, respectively. The pulse repetition rate is 143 Hz, and the pulse width varies from 100 ns to 200 ns as the pump power changes. In designing this laser, a new cavity length adjustment configuration of a double optical wedge was employed, achieving a maximum adjustment length of ΔL = 3.62 μm; the procedures for injecting the seed laser and detecting the resonance signal were analyzed, proving the feasibility of applying a DCCR ring cavity to an injection-seeded Q-switched laser.