High pulse energy ZnGeP2 OPO directly pumped by a Q-switched Tm3+-doped single-oscillator fiber laser

A mid-infrared ZnGeP2 optical parametric oscillator pumped by a Tm3+-doped fiber laser is reported, providing pulse energies of 230µJ, pulse widths of 40 ns, and peak powers of ∼6kW with excellent efficiency and beam quality. The pump source is an actively 𝑄-switched single oscillator optimized to generate high pulse energies.