Second-harmonic generation in Ti-diffused LiNbO3 optical waveguides with 25% conversion efficiency

Using a tunable optical parametric oscillator, phase-matched second-harmonic generation was realized in high-quality Ti-diffused LiNbO3 optical waveguides near the 1.08-μ fundamental wavelength. At 45 W peak power in 17-mm-long waveguides an efficiency for TM0→TE1 conversion up to 25% was achieved. This value is three orders of magnitude larger than previously published results.