TYPE-II PHASE MATCHING IN A BETA-BARIUM BORATE OPTICAL PARAMETRIC OSCILLATOR

We report the first demonstration of a type II phase-matched optical parametric oscillator using β-barium borate (BBO) as the nonlinear optical material. The optical parametric oscillator (OPO) is pumped at 354.7 nm and tuning has been demonstrated over 0.48-0.63 μm and 0.81-1.36 μm. The linewidth of the device, without line narrowing elements, is 0.5-3.0 Å, which is dramatically narrower than that of a corresponding type I phase-matched BBO OPO. Experimentally usable conversion efficiencies of 12% have been achieved.