Stabilized diode laser pumped, idler-resonant cw optical parametric oscillator

We present a diode laser pumped continuous wave, pump-enhanced singly-resonant optical parametric oscillator (OPO). The cavity is stabilized by a Pound–Drever–Hall scheme using direct modulation of the diode laser. The system provides stable signal powers of up to 220 mW. The wavelength can be tuned between 1.40–1.60 μm for a ring or a linear cavity design by changing the crystal temperature. The relative fluctuations of the stabilized OPO’s wavelength are less than 10−7 for more than one hour. Using a self-heterodyne technique, we measure a linewidth of the signal wave of 3.5 MHz.