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Multimode waveguide Bragg gratings on SOI platform

Multimode waveguide Bragg gratings (MWBGs) are demonstrated on silicon-on-insulator (SOI) platform for on-chip applications, such as band-pass and band-rejection filter, add-drop filter, polarization beam splitter and mode multi/demultiplexers. The operating principle is based on the contra-directional coupling between the fundamental transverse electric mode and different higher-order modes, which depends on the symmetry or the asymmetry properties of the periodic refractive-index perturbations. The designs and experimental results of different MWBGs based devices are presented.