Efficient 1.5-µm-Band MgO-Doped LiNbO3 Quasi-Phase-Matched Wavelength Converters

1.5-µm-band wavelength converters based on cascaded χ(2) in periodically poled MgO:LiNbO3 (PPMGLN) waveguides are fabricated and studied for the first time. A conversion efficiency of -26 dB is obtained with the pump power of only 16 mW, which is compatible with the highest reported value of the PPLN wavelength converters based on nondoped substrates. The 3 dB conversion bandwidth is found to be as large as 68 nm for a 45-mm-long device.