Study and fabrication of add/drop filter based on Bragg gratings reflection coupler

The coupler-mode equation for analysing Bragg grating reflection coupler was presented. The influences of different gratings' position in the coupling region and grating length on the filtering spectra were investigated based on the equation. A Bragg grating reflection coupler with reflectivity 20dB was achieved by fused taper technology and Phase Mask methed.