The modulation asymmetry of a multifunction integrated optic circuit (MIOC) indicates the difference in the phase response to modulation electric fields with the same magnitude but different directions, and is partly caused by the vertical component of the modulation signal. This introduces a nonlinear phase error that is difficult to compensate in fiber optic gyroscopes (FOGs), which needs to be suppressed. In this paper, a sinking-electrode MIOC design to suppress the modulation asymmetry is proposed and verified through numerical simulations. Optimal parameters of the gap, height, side-wall angle, and center position error of the sinking electrodes are obtained on the basis of the simulation results. With the proposed method, the modulation asymmetry of MIOC can be reduced from $5\times 10 ^{-4}$ rad to $1\times 10 ^{-6}$ rad, thus facilitating the development of high-performance FOGs. Furthermore, compared with the traditional electrode design, the sinking-electrode design can increase the tolerance for the manufacturing process, and the design configuration can be obtained through the general process method.

中文翻译：

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下沉电极抑制多功能集成电路的调制不对称性

多功能集成光路 (MIOC) 的调制不对称性表示对大小相同但方向不同的调制电场的相位响应不同，部分原因是调制信号的垂直分量。这引入了光纤陀螺仪 (FOG) 中难以补偿的非线性相位误差，需要加以抑制。在本文中，提出了一种抑制调制不对称性的下沉电极 MIOC 设计，并通过数值模拟进行了验证。根据仿真结果得到下沉电极的间隙、高度、侧壁角度和中心位置误差的最佳参数。使用所提出的方法，可以将 MIOC 的调制不对称性从 $5\times 10 ^{-4}$ 拉到 $1\times 10 ^{-6}$ rad，从而促进高性能 FOG 的开发。此外，与传统的电极设计相比，下沉电极设计可以增加制造工艺的公差，并且可以通过一般工艺方法获得设计配置。