1.5 μm band efficient broadband wavelength conversion by difference frequency generation in a periodically domain-inverted LiNbO3 channel waveguide

Efficient 1.5 μm band wavelength conversion by difference frequency generation (DFG) in a periodically domain-inverted LiNbO3 channel waveguide is demonstrated, and DFG efficiency as high as 40% W−1 cm−2 is obtained. Nearly constant wavelength conversion efficiency has been confirmed over a broad wavelength range of 30 nm, which is the largest value ever reported.