The Research Center of Semiconductor, Functional Film Engineering Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, 865 Changning Road, Shanghai 200050, PR China
Abstract:
A novel compact 3-dB coupler is proposed and fabricated in silicon-on-insulator. The new coupler provides large output waveguide spacing of 125.0 μm with short device length of 867.0 μm and large cross-section of 6.0 × 4.0 μm. The device length can be remained essentially unchanged even when the output spacing is further enlarged to realize the complex applications in photonic integrated circuits. The fabricated device exhibits excess loss of 6.3 dB and low imbalance of 0.26 dB.