Non-planar image-rotating cavities allow to reach 30 W of average power in mid-IR with good beam quality from high-repetition-rate ns-pulsed ZGP OPOs

Abstract

We discuss main challenges in scaling up the output power of high-repetition-rate optical parametric oscillators (OPOs), that are nowadays the most promising technology to reach the level of output power of a few tens of W with reasonably good beam quality (M2 < 2) in middle infrared spectral region. We report the the performance at 30 W level of output power of an OPO based on ZGP crystals in two non-planar image-rotating resonators. Factors influencing the beam quality such as average power and pump repetition rate are studied in detail.