设计了一种可用于阵列波导光栅(AWG)解调集成微系统的绝缘体上硅(SOI)基2×2多模干涉(MMI)耦合器,用光束传播法(BPM)对MMI耦合器进行了模拟。耦合器输入/输出波导采用倒锥形,多模干涉区尺寸为6μm×57μm。在TE偏振中心波长为1.55μm时,器件附加损耗为0.46dB,不均匀性为0.06dB。在1.49～1.59μm波长范围内耦合器的附加损耗小于1.55dB。仿真结果表明所设计的2×2MMI耦合器体积小、附加损耗低、波长响应范围宽、分光均匀,符合片上集成系统的要求。 A silicon-on-insulator (SOI) based 2 × 2 multimode interference (MMI) coupler that can be used for AWG demodulation integrated microsystems was designed. The MMI coupler was beam-propagated (BPM) simulation. The coupler input / output waveguide is inverted conical, and the multimode interferometer size is 6 μm × 57 μm. When the center wavelength of TE polarization is 1.55μm, the additional loss of the device is 0.46dB, and the non-uniformity is 0.06dB. In the wavelength range of 1.49 ~ 1.59μm additional loss of the coupler is less than 1.55dB. The simulation results show that the designed 2 × 2MMI coupler has the advantages of small size, low additional loss, wide wavelength response range and uniform light distribution, which meets the requirements of on-chip integrated system.