Direct-bonded QPM-LN ridge waveguide with high damage resistance at room temperature

A direct-bonded 13 mm-long quasi-phase matched LiNbO3 (QPM-LN) ridge waveguide is fabricated that exhibits a second-harmonic generation efficiency of 44%/W: The waveguide shows very high resistance to photorefractive damage at room temperature. The difference frequency generation with an efficiency of -17.6 dB in the 1550 nm wavelength band is also demonstrated.