Phase-locked picosecond optical parametric oscillator.

We report a degenerate self-phase-locked picosecond optical parametric oscillator (OPO) synchronously pumped by a mode-locked Yb-fiber laser at 1064 nm, delivering broadband output near 2 mu m with 2.8 W of average power at similar to 80 MHz repetition rate. By exploiting a 50-mm-long MgO:PPLN crystal providing high gain and low group velocity dispersion under type-0 (e -> ee) phase matching, the OPO generates a phase-locked degenerate output spectrum with a bandwidth of similar to 202 nm centered at 2128 nm in pulses of similar to 21 ps duration with excellent passive long-term power and spectral stability in high spatial beam quality. Phase-locked operation results in spectral and power stabilization at exact degeneracy and is further validated by f - 2f interferometry and radio frequency measurements of OPO output. To the best of our knowledge, this is the first degenerate self-phase-locked OPO in picosecond time scale, and the highest average power reported for a phase-locked ultrafast OPO to date. (C) 2020 Optical Society of America