Optical variable-in variable-out wavelength converters based on MgO doped LiNbO3 quasi-phase matched waveguides

In conclusion, all optical variable-in variable-out wavelength conversions have been proposed and demonstrated for the first time, by changing the device temperature and pump wavelength of MgO doped LiNbO₃ QPM waveguides. It is shown that the converted light can be tuned in a wavelength range of 30 nm by changing the device temperature between 20 ∼ 150°C for a fixed signal wavelength, while the signal wavelength can take any value in a wavelength range of 60 nm. Conversion efficiency as high as -26 dB (-6 dB expected) at a pump power of -0.5 dBm (+20 dBm) is achieved in a 4.5-cm-long MgO:LiNbO₃ QPM-DFG wavelength converter. Features of MgO doped LiNbO₃ QPM devices such as high efficiency, broad conversion bandwidth and variable-in variable-out wavelength conversions are very attractive for future optical communication systems.