CW solid-state ultraviolet laser for optical disk mastering application

We have built a prototype laser head that emits 355-nm ultraviolet light in CW mode. The system is based on nonlinear sum-frequency mixing using a /spl beta/-BaB/sub 2/O/sub 4/ (BBO) crystal in an external resonator in which two input emissions at 1064 and 532 nm are resonantly enhanced simultaneously. The output exhibits promising characteristics as the master recording laser source, in terms of beam shape and intensity stability. The result of reliability testing of the system in 1000-h real-time operation is also discussed.