Broadband Sheet Parametric Oscillator for \chi^(2) Optical Frequency Comb Generation via Cavity Phase Matching

We demonstrate a broadband optical parametric oscillation, using a sheet cavity, via cavity phase-matching. A 21.2 THz broad comb-like spectrum is achieved, with a uniform line spacing of 133.0 GHz, despite a relatively large dispersion of 275.4 fs^2/mm around 1064 nm. With 22.6% high slope efficiency, and 14.9 kW peak power handling, this sheet optical parametric oscillator can be further developed for \chi^(2) comb.