针对一种错位型MEMS(Micro－Electro－Mechanical Systems)可调光衰减器，基于输入输出光纤间模场的交叠积分，数值分析了径向偏差和轴向间隙同时存在的情况下，光功率衰减量与错位量和波长的关系．演示了利用闭环反馈控制系统提高器件响应线性度的显著效果．研制出样机并测量得到器件的响应时间(约1．5ms)，动态范围(约35dB)，波长相关损耗(＜0．4dB)，偏振相关损耗(＜0．1dB)等关键性能参量．

The attenuation characteristic of a MEMS (Micro-Electro-Mechanical Systems) Variable Optical Attenuator has been studied. Via numerical analysis,the relationship between attenuation and the misalignments (lateral misalignment and longitudinal gap) has been analyzed. It has been demonstrated that the linearity of the device could be improved tremendously via close-loop control system. The key performances of the close-loop controlled Variable Optical Attenuator are measured,including response time (about 1.5 ms),dynamic range (about 35 dB),Wavelength Dependent Loss (< 0.4 dB),and Polarization Dependent Loss (<0.1 dB).