A LD side-pumped deep ultraviolet laser at 266 nm by using a Nd:YAG/Cr4+:YAG/YAG composite crystal

• The novel composite crystal Nd:YAG/Cr:YAG/YAG reduced the thermal effect greatly.
• The compact side-pumped system has a high average output power of 1.27 W.
• Laser system at 266 nm with a compact structure and low cost.
• A multi-reflected cavity for 532 nm is used for obtaining high conversion efficiency.
• The compared result is significant to theoretical research and practical application.

A stable and compact deep ultraviolet laser system operation at 266 nm with diode-side-pumped and passively Q-switched is reported. The Nd:YAG/Cr4+:YAG/YAG composite crystal is used in realizing fundamental laser output and passively Q-switched modulation and for achieving a high conversion efficiency from 532 nm to 266 nm; a multi-reflected cavity for 532 nm is used in the system. The performances of the average power, pulse width, and pulse repetition rate on pump power are measured. Under the green laser of 13.03 W, the deep ultraviolet laser average output power of 1.27 W is obtained, with a pulse width of 60 ns, the repetition rate of 12.5 kHz, and the corresponding conversion efficiency of 9.74%.