无交叠垂直梳齿平动微镜的驱动特性

为了设计用于光相位调制器平动微镜的无交叠梳齿驱动器,建立了保角变换数学模型,研究了驱动器的驱动特性。从复变函数理论出发,建立了驱动器的保角变换静电场解析模型;以动齿受力为研究对象,根据不同情形下的动齿受力特点,求解了一定区间内动齿的静电力并与有限元模拟计算结果进行了对比分析。采用微机电系统(MEMS)工艺制作出了无交叠梳齿驱动器,搭建了Michelson干涉仪光学测试系统,测试了无交叠梳齿驱动器的静态驱动特性。实验结果表明,所制作的无交叠梳齿驱动器在28V偏压下机械位移可达325nm,相位差为2π;在90V的偏压下能够获得2.07μm静态位移。测试结果与保角变换及有限元模型分析结果一致,验证了所建数学模型的正确性,为无交叠梳齿驱动器的设计提供了理论与实验基础。

Driving characteristics of non-overlap vertical electrostatic combdriver for optical translational micromirror

To design a non-overlap vertical electrostatic combdriver for the optical translational micromirror of an optical phase modulator, a mathematic model based on the conformal mapping was built to research the driving performance of the combdriver in detail. According to the theory of complex variable function, an analytical model was established for the electrostatic field of comb actuator by conformal mapping. Then, the electrostatic force in a certain displacement range was deduced by the analytical model for researching the movable comb finger. The results were compared with the corresponding resolution by the Finite Element Method (FEM). Finally, a non-overlap vertical combdriver was successfully fabricated by Micro Electronic Mechanic System(MEMS) process, and an optical Michelson interference system was constructed to measure the static driving charateristics of the comb driver. The result shows that the displacement of proposed non-overlap vertical electrostatic combdriver is 325 nm (phase difference 2π) with a dc driving voltage of 28 V and the offset vertical comb actuator can be actuated to 2.07 μm under a dc driving voltage of 90 V. The measured results accord excellently with the simulated results using the conformal mapping and FEM method, which proves proposed analytical model to be correct. It can provide theoretical and pratical bases for design of non-overlap vertical electrostatic combdrivers.