Dual-mode waveguide crossing utilizing taper-assisted multimode-interference couplers

A dual-mode waveguide crossing is proposed and realized for the application of on-chip multimode interconnection. The present structure is realized by two 90 degrees crossed multimode-interference (MMI) couplers. By properly choosing the width and length of the MMI section, the self-images for both the incident TM0 mode and the TM1 mode could be at the center of the crossing. The characterization results for the fabricated device show that low insertion loss below similar to 1.5 dB and low crosstalk below similar to-18 dB can be achieved over a large bandwidth more than 80 nm for both the TM0 and TM1 modes. (C) 2016 Optical Society of America