Numerical and experimental investigations of chirped-gratings-based Bragg-reflecting-coupler with multiple couple lengths

Influences of gratings’ chirp and coupler’s length on the spectral responses of Bragg-reflecting-coupler are investigated detailedly. Both numerical and experimental results demonstrate that signals outside of the gratings’ stopband can be guided to any of transmission ports by adjusting the couple length. But for signals within the gratings’ stopband, multiple interference peaks appear alternately in the two reflection ports, which provides the feasibility to fabricate add/drop filter operating on more than one channel simultaneously.