High power and conversion efficiency intracavity ultraviolet laser at 355 nm

In this study, we investigated and provided a compact and efficient diode-pumped-solid-state ultraviolet laser at 355 nm with high commercial value. The 355 nm laser was coupled out with an uncoated Brewster-cut LBO crystal in order to prolong its lifetime. A maximum output power of 12.2 W was generated when pump power was 74.5 W and the pulse repetition rate was 40 kHz. The conversion efficiency from pump laser to ultraviolet laser was 16.4 %, which we believe to be the highest among the reported papers in which the pump source was 887 nm. The stability of 355 nm laser power was less than ± 1 % at 12 W over 20 h. Output characteristic of ultraviolet beam varying with the temperature of two LBO crystals was also investigated to located the exact optimal operating temperature.