Design of a grating-assisted silicon hybrid mode-, polarization-, and wavelength-division (De)multiplexer for on-chip...

This paper presents a 12-channel hybrid mode-, polarization-, and wavelength-division (de)multiplexer. The proposed device is designed on a silicon-on-insulator platform. The device structure constitutes three coupling sections with a bus waveguide at the middle and two single-mode waveguides on each side. The periodic grating structures are present in between the waveguides for contra-directional coupling of the three TE modes and three TM modes of the bus waveguide to respective fundamental modes of the single-mode waveguides at 1550 and 1560 nm. The device is simulated using the 3D finite-difference time-domain technique, and the resulting insertion loss, cross talk, and return loss are <1.56dB, <-21.74dB, and >12.22dB, respectively. Moreover, the period of the grating structures is varied to perform the fabrication tolerance study.