A tunable wavelength-interchanging cross-connect scheme utilizing two periodically poled LiNbO3 waveguides with double-pass configuration

A tunable wavelength-interchanging cross-connect (WIXC) scheme is proposed by utilizing two periodically poled LiNbO3 waveguides. A fiber Brag grating is utilized to link the two waveguides so as to configurate the double-pass operation. In each waveguide, sum frequency generation (SFG) and difference frequency generation (DFG) take place during the forward propagation and backward propagation, respectively. The two tunable pumps, utilized in the processes of SFG and DFG respectively, are arranged to select an arbitrary channel from a WDM signal and convert it to an arbitrary wavelength. The information carried by two different wavelengths in two different WDM signals can be interchanged by tuning the frequencies and powers of the two pumps.