Broadly tunable optical parametric oscillation in β-BaB2O4

We report the first successful operation of a β-BaB2O4 optical parametric oscillator (OPO) tunable in the visible and the near infrared. The OPO was pumped at 354.7 nm and was tunable throughout 0.45–1.68 μm. A maximum total energy conversion efficiency of 9.4% was measured from the OPO containing a 10.5 × 10.5 mm2 × 11.5 mm long, 30° cut β-BaB2O4 crystal grown in our laboratory. Using the optical parametric luminescence technique, we have measured the 354.7 nm and 266 nm pumped OPO tuning curves (type I and type II) in β-BaB2O4 throughout the ∼0.3–3.3 μm range. The implication of these results on the validity of the published Sellmeier equations is discussed.