Wavelength filtering characteristics of Solc filter based on Ti:PPLN channel waveguide.

We have analyzed the Solc filtering characteristics in a periodically poled Ti:LiNbO3 (Ti:PPLN) multimode waveguide. The single- and dual-wavelength filtering were achieved under the optimized guiding condition for the TEM00-like mode and two mode (TEM00- and TEM01-like mode), respectively. The full width at half-maximum of the filter was about 0.21 nm at both guiding conditions. We found that the origin of two peaks of the dual-wavelength Solc filter in the two-mode guiding condition is the different effective refractive index between the TEM00- and TEM01-like modes. The wavelength difference of two peaks is about 0.8 nm at room temperature.