Toward integrated tantalum pentoxide optical parametric oscillators

We present a hybrid waveguide-fiber optical parametric oscillator (OPO) exploiting degenerate four-wave mixing in tantalum pentoxide. The OPO, pumped with ultrashort pulses at 1.55 $\mu$m wavelength, generated tunable idler pulses with up to 4.1 pJ energy tunable between 1.63 $\mu$m and 1.68 $\mu$m center wavelength. An upper bound for the total tolerable cavity loss of 32 dB was found, rendering a chip-integrated OPO feasible as a compact and robust light source.