Broad tuning around degeneracy in a singly resonant synchronously pumped parametric oscillator by means of a diffraction grating

The use of a diffraction grating as a frequency-selective reflector, has allowed a synchronously pumped optical parametric oscillator based on periodically poled lithium niobate to tune over a wide range, 1900-2300 nm around degeneracy (2094 nm), on a single periodically poled lithium niobate grating at a fixed temperature. The grating ensures stable singly resonant operation over the whole of this range except for a very narrow range at degeneracy, where doubly resonant behavior is evident. The extent of this narrow range, ~6 nm, is confirmed by analysis.