摘要
An optical 90° hybrid based on an InP 4 × 4 multimode interference (MMI) coupler is designed and fabricated for the application in a coherent receiver.It reveals that the width of multimode waveguide is the most critical parameter for the devices,and the multimode waveguide width can be accurately controlled within 0.1 μm in our experiments.Across the entire C-band (1527-1561 nm),the maximum imbalance of the devices is less than 0.7dB,and the common mode rejection ratios for in-phase channels and quadrature channels are better than - 24 dB.
基金
Supported by the National Natural Science Foundation of China under Grant No 61076042
the Special Project on Development of National Key Scientific Instruments and Equipment of China under Grant No 2011YQ16000205
the National Key Technology R&D Program of China under Grant No 2009BAH49B01
the National High Technology Research and Development Program(863 Program)of China under Grant Nos 2011AA03A106 and 2011AA010304,Science and Technology Special Project in Hubei Province(No 2009AAA009)
the Natural Science Foundation of Hubei Province(No 2010CDB01606)
the Research Funds for the Central Universities(HUST No 2011QN036).
