Optical 90° hybrid based on silicon-on-insulator 4×4 multimode interference coupler for integrated coherent receiver application

An optical 90° hybrid based on Silicon-on-Insulator (SOI) 4×4 multimode interference(MMI) coupler is designed and simulated for the application of integrated coherent receiver(ICR). The beam propagation method(BPM) is used to verify the performance of the device. The 4×4 MMI coupler show good performance over C-band of TM mode with wavelength dependent loss(WDL) <;0.3 dB, output power imbalance <;0.35dB, phase error better than 2°.