Temporal optical parametric oscillator

We present a new class of optical resonator: the temporal optical parametric oscillator (temporal OPO) which is a cavity constructed around a time-lens in a 2f configuration, enabling light to oscillate not in space, but in time. Unlike conventional OPOs, the temporal OPO exhibits roundtrip Fourier transforms, mapping time into frequency and vice versa, giving rise to a cascade of novel nonlinear effects. We explore the generation of soliton pairs under negative dispersion, enabled by effective dispersion inversion, and observe ultrafast oscillatory dynamics driven by nonlinear polarization mode dispersion. The temporal OPO combines parametric gain, dispersion control, and spectral–temporal feedback, offering a rich platform for exploring high-speed dynamics, soliton interactions, and time-frequency duality in nonlinear optics. This work opens the door to temporally-engineered resonators with potential applications in ultrafast signal processing, temporal spectroscopy, and optical computing.