Measurement and Analysis of Cavity Loss of a 266 nm Continuous-Wave Solid-State Laser

The effect of purge air on the reliability of a 266 nm continuous-wave (cw) solid-state laser was analyzed by measuring the cavity loss of an ultraviolet (UV) laser. The water content of the purge air strongly connected with the reliability of the laser. Irradiation by UV laser beam and existence of water around a mirror in an external cavity created scatterers on the surface of the mirror. The scatterers increased the cavity loss of the UV laser and markedly decreased the UV laser power.