Over ten-millijoule eye-safe laser generation by extra-cavity optical parametric oscillator driven with a diode-pumped Nd:YAG/Cr4+:YAG Q-switched laser

Abstract

An efficient diode-side-pumped Nd:YAG/Cr4+:YAG Q-switched laser with a convex-concave resonator is employed to develop a high-pulse-energy eye-safe laser. We utilize a monolithic KTP crystal to be the optical parametric oscillator (OPO) crystal, and to form an extracavity OPO configuration. Based on the efficient Nd:YAG laser oscillator at 1064 nm carrying a pulse energy of 30 mJ, the OPO energy at 1573 nm of 13.3 mJ is obtained with a pulse width of 6 ns, corresponding to an OPO conversion efficiency of 44.3%.