High-efficiency CW all-fiber parametric oscillator tunable in 0.92-1 μm range.

Continuous tuning over 80 nm is demonstrated for the anti-Stokes wave generated in an optical parametric oscillator (OPO) based on a birefringent photonic crystal fiber pumped by a CW Ytterbium-doped fiber laser tuned around 1.05 μm (within 4 nm only). An influence of the pump laser linewidth and polarization state on the fiber OPO threshold and efficiency is studied. Slope efficiency of parametric generation at 931 nm reaches 19% for ~0.1 nm linearly polarized pump with threshold power of ~5W. At that, the generated linewidth amounts to about 1 nm.