Extended mode-hop-free tuning by use of a dual-cavity, pump-enhanced optical parametric oscillator

We report extended mode-hop-free tuning in a continuous-wave, pump-enhanced optical parametric oscillator (PE-OPO). We employ a dual-cavity configurat ion to allow independent control of the resonant pump and signal fields, an d so we can suppress frequent mode hops in the signal as the pump is tuned in frequency. With the signal field clamped in frequency by an uncoated eta lon, the idler field can be scanned smoothly through a range of 10.8 GHz. T he PE-OPO outputs can also be tuned coarsely from 1.01 to 1.18 mu m in the signal and from 2.71 to 3.26 mu m and 4.07 to 5.26 mu m in the idler. We fi nd that increased idler absorption only slightly increases the oscillation threshold. (C) 2000 Optical Society of America. OCIS codes: 190.2620, 190.4 360, 190.4970.