A 1-THz optical frequency shifter using quasi-phase-matched LiNbO/sub 3/ wavelength converters

We proposed a novel optical frequency shifter based on double wavelength conversion. The magnitude and the direction of the shift of the optical frequency shifter can be tailored by choosing the frequency difference between the two pump lights in double wavelength conversion. The shifter can convert input signals to destination channels that contain common channels. We also demonstrated multi-channel shifting of the proposed optical frequency shifter using two quasi-phase-matched LiNbO/sub 3/ wavelength converters. A broad-band frequency shift as high as 1 THz was achieved. This broad-band optical frequency shifter can facilitate the construction of future WDM optical communication systems.