2.5-W, CONTINUOUS-WAVE, 629-NM SOLID-STATE LASER SOURCE

We report an efficient, high-power, cw, 629-nm laser source based on a diode-pumped Nd:YAG laser and a periodically poled lithium niobate (P PLN) frequency converter. This device integrates two separate frequenc y-conversion steps in a single crystal, taking advantage of the abilit y to fabricate PPLN with nearly arbitrary grating periods and phase-ma tching temperatures. This device uses a single PPLN crystal that has t wo grating regions in series. The first region quasi-phase matches a s tandard optical parametric oscillator process (1064 nm --> 1540 nm + 3 450 nm), and the second region quasi-phase matches a sum-frequency pro cess whereby the pump and the signal light make red light (1064 nm + 1 540 nm --> 629 nm). Using a four-mirror ring cavity, we were able to c onvert 21% of the 1064-nm pump to 629-nm output, yielding 2.5 W of red output with 11.8 W of input. (C) 1998 Optical Society of America.