Parametric oscillator directly pumped by a 1.55-μm erbium-fiber laser

We report what is believed to be the first demonstration of an optical parametric oscillator directly pumped by the 1.55-mu m output of an erbium-doped fiber laser. The oscillator, based on periodically poled lithium niobate, produced 8-mu J idler output near 3.8 mu m at a 500-Hz repetition rate when it was pumped with 100-mu J 66-ns pulses at 1.55 mu m. Temperature tuning of the 50-mm-long PPLN crystal gave signal and idler ranges of 2.55 to 2.7 mu m and 3.65 to 3.96 mu m, respectively, limited by mirror reflectivity. A signal-tuning range of 40 nm was observed for 13.5 nm of pump tuning with a fixed grating period and temperature. The optical parameter oscillator could be operated at low temperature with no sign of photorefractive damage. of America OCIS codes: 190.4970, 140.3510.