设计和制作了应用于微波全双工收发系统的马赫-曾德尔型电光双向强度调制器。根据电光调制器中电信号对光信号的调制叠加原理, 通过计算和仿真, 分析了因调制电极设计电场与实际电场分布差异导致的器件隔离度劣化。通过对比不同调制电极结构的分析设计和仿真优化结果, 得到3.5GHz以上频段隔离度优于-30dB的电光双向强度调制器设计结构。制备出的电光双向强度调制器在5~17GHz范围内隔离度优于-30dB。

In this paper, a kind of bidirectional electro-optic Mach-Zehnder intensity modulator was designed for microwave full-duplex transceiver system. According to the principle of modulation and superposition of electric signals to optical signals in the electro-optic modulator, analyzed is the deterioration of isolation caused by the distribution difference between the designed electric field and the actual electric field of the modulated electrode. By comparing the analysis, design and simulation results of different modulation electrode structures, it is concluded that the bidirectional electro-optic intensity modulator with the isolation better than -30dB above 3.5GHz is fabricated successfully, achieving an isolation better than -30dB in the range of 5~17GHz.