Optimization of contra-directional coupler based on silicon nitride Bragg rib waveguide
We report on the development and fabrication of a contra-directional coupler based on the Bragg waveguide on Si 3 N 4 platform. Transmitted and reflected by the contra-directional coupler spectra were measured. The reflected spectra exactly matches the one notched by the main channel of the coupler. Losses are about 3dB, coupling to the directing branch of the coupler is practically lossless. FWHM of the transmitted (reflected) spectra is 3.46 nm.