Low-repetition-rate near-infrared femtosecond pulse generation in a harmonically pumped idler-resonant optical parametric oscillator

We demonstrate, to the best of our knowledge, the first harmonically pumped idler-resonant optical parametric oscillator (OPO). Exploiting the synchronous behavior of an ultrafast OPO, we generate 49.16-MHz non-resonant signal pulses using a 49.16-MHz Yb:fiber laser as a pump source by constructing idler-resonant OPO cavities up to the 6 th harmonic at 294.96 MHz, with 100-mW-level signal outputs tunable across 1680-2000 nm. We investigate the suitability to this approach to realize high-energy near-infrared pulses in a compact footprint via the non-resonant signal wave.