CW 355 nm Generation by Doubly-Resonant Sum-Frequency Mixing in an External Resonator

Resonating both inputs at 532 nm and 1064 nm in an extemal resonator, sum-frecluency output at 355 nm was obtained A type-I phase-matched BBO crystal that is fabricated at near-Brewster cut served as the nonlinear medium, maintaining the low-loss at both input wavelengths. 220 mW of cw ultraviolet output at 355 nm was obtained.