Efficient intra-cavity continuous-wave periodically poled lithium niobate-doped MgO optical parametric oscillator with compact V-type cavity

A compact efficient intra-cavity singly resonant optical parametric oscillator (OPO) based on periodically poled lithium niobate-doped MgO (MgO:PPLN) was investigated. A concave-concave fundamental cavity was used for focusing the fundamental beam waist on MgO:PPLN crystal, which enables more compact setup and less insertion loss than traditional insertion of a focusing lens. Two V-type OPO cavities with single and double outputs were used for comparison with idler light outputting from one and both end mirrors, respectively. The results show that the double outputs configuration achieved higher output power for its advantage of reducing the reversed OPO process and diffraction loss of the idler light. Under an incident pump power of 12.4W, a maximum signal output power of 2.89W at 1549 nm and total idler output power of 1.44W at 3394 nm were obtained with a total conversion efficiency up to 34.9%. (C) 2018 The Japan Society of Applied Physics