A schematic diagram of a combined polarization rotator and mode converter provides mode conversion to reduce propagation loss in the waveguide while retaining the original polarization state
Silicon is the dominant material for the fabrication of integrated circuits and is also becoming a popular material for making photonics circuits—miniaturized circuits that use light instead of electronic signals for processing information. One of the challenges in the field, however, has been silicon’s intrinsic sensitivity to the polarization of light, which can limit the rate of information transmission. Jing Zhang, Tsung-Yang Liow and co-workers at the A*STAR Institute of Microelectronics have now developed a novel solution to this problem
A silicon waveguide based TE mode converter was designed for the mode conversion between a horizontal waveguide and vertical waveguide in the two-layer structure waveguide based polarization diversity circuit. The TE mode converter’s performance was studied. The polarization mode converter with minimum length of 5μm was demonstrated to provide the TE mode conversion while maintaining the polarization status. The insertion loss at the transition region was less than 2dB.