Abstract

We report an efficient, high power, continuous-wave, 629 nm laser source based on a diode-pumped Nd:YAG laser and a periodically poled lithium niobate (PPLN) frequency converter. This device integrates two separate frequency conversion steps in a single crystal, taking advantage of the ability to fabricate PPLN with nearly arbitrary grating periods and phasematching temperatures. This device uses a single PPLN crystal that has two grating regions in series. The first region quasi-phasematches a standard optical parametric oscillator (OPO) process (1064 nm 1540 nm + 3450 nm), while the second region quasi- phasematches a sum frequency process whereby the pump and the signal light make red light (1064 nm + 1540 nm ➝ 629 nm). Using a 4-mirror ring cavity, we were able to convert 21% of the 1064 nm pump to 629 nm output, yielding 2.5 W of red output with 11.8 W of input.

© 1998 Optical Society of America