MEMS微变形镜的系统级建模研究

【作者】 何洋；

【导师】 姜澄宇；

【作者基本信息】 西北工业大学 ， 机械电子工程， 2005， 硕士

【摘要】 微型自适应光学系统在天文观测、激光武器和现代医学高分辨率成像等领域有着重要的应用前景,基于MEMS技术的微变形镜是微型自适应光学系统的核心器件,涉及光相位调制、机电耦合等诸多方面的研究。如何建立MEMS微变形镜准确有效的光相位调制和机电耦合的系统级模型,从而快速得到其可靠的仿真结果,以减少设计成本,缩短开发周期,便成为微型自适应光学系统设计的一个重要问题。 本文以微型自适应光学系统的关键部件微变形镜为研究对象,研究了微变形镜系统级建模的方法,建立了微变形镜的系统级模型,并实现了微变形镜阵列的仿真。论文的主要研究内容包括: 研究了微变形镜的机电行为建模方法并建立了机电组件模型。基于多端口组件网络方法,采用能量法建立了机电功能组件弹性梁、平板质量块的力学行为模型,应用机电能量转换原理建立了平板式可变电容器的机电耦合行为模型。使用硬件描述语言MAST编码实现了多端口组件模型并将仿真结果与有限元分析结果进行了精确性比较,仿真结果表明模型具有较高的精度,能够实现快速仿真。 研究了微变形镜的光学行为建模方法并建立了光学组件模型。确定了光信号的描述方法,采用几何矩阵光学和高斯光束的理论建立了光学元件平面反射镜和薄透镜的光学模型,用硬件描述语言MAST编码实现了多端口组件模型并进行了光学仿真。研究了微变形镜阵列光学性能的评价指标斯特列尔比和适配误差,建立了阵列光学性能评价的多端口组件模型,并分析了阵列参数对阵列光学性能的影响。 建立了微变形镜系统级模型并实现了系统仿真。建立了微变形镜机电行为系统级模型,进行了频域仿真分析、时域仿真分析和直流瞬态分析,得到了微变形镜的谐振频率、响应时间和吸合电压等重要性能指标,表明所设计的微变形镜满足自适应光学系统的要求。首次建立了微变形镜阵列的光相位调制系统级模型。进行了阵列光相位调制仿真分析,得到了对畸变波前调制后的输出波前,并分析了相对误差。仿真结果表明使用本文所述方法,可以实现微变形镜阵列的系统快速建模与仿真分析,有利于微变形镜阵列的设计与优化。更多还原

【Abstract】 Micro deformable mirror fabricated by MEMS technologies is one of the core components of the micro-mechanical adaptive optics system which is widely implemented in many fields such as telescope systems, laser beam weapons, medical high-resolution imaging systems and laser communication systems. In order to reduce the cost and shorten the design cycle, accurate and efficient system level modeling of micro deformable mirror involving optical phase modulation and mechanical and electrostatic coupling would invariably be needed.In the thesis, system level modeling methodology is presented for rapid modeling and simulation of micro deformable mirror. Based on the method, the system level model of the micro deformable mirror is established and simulated. The main contents of this thesis are as following:Firstly, The modeling methodology of mechanical and electrostatic behavior of the micro deformable mirror is presented and the models are established accordingly. Based on Multi-Port-Element Network(MuPEN) method, the mechanical model of the spring beam and the rigid plate mass is established according to law of energy conservation, while the mechanical and electrostatic coupling model of electrostatic gap is established based on mechanical and electrostatic energy transition principle. Meanwhile, all models are coded in analog hardware description language (MAST). Furthermore, the accuracy of models is verified by comparison with finite element analysis(FEA) and the results prove that the models have near FEA accuracy.Secondly, The modeling methodology of optical behavior of the micro deformable mirror is investigated and the models are established as a result. The description of optical signal is presented and the behavior model of the optical functional components such as planar reflection mirror and thin lens are established using matrix optics and Gaussian beam theory. The models are coded in analog hardware description language(MAST) and are simulated in MuPEN. In addition, the evaluation parameters of the optical quality for the micro deformable mirror arraysincluding the Strehl ratio and fitting error are analyzed. Then, MuPEN models for optical quality evaluation are established and simulation is implemented to analyze the effect of the parameters of mirror arrays on optical quality.Finally, system-level model of micro deformable mirror is established and both mechanical and electrostatic coupling simulation and optical phase modulation simulation are implemented in MuPEN. The resonance frequency, the response time and the pull-in voltage of the micro deformable mirror are ascertained through different simulations and the simulation results show that the micro deformable mirror we designed can satisfy the requirements of adaptive optics system. Moreover, the optical phase modulation behavior model of micro deformable mirror arrays is established for the first time. Then the simulation is implemented and the wavefront after phase modulation is reconstructed together with the analysis of relative error. Simulation results indicate that rapid modeling and simulation of micro deformable mirror can be accomplished in this way which will benefit the design and optimization of micro deformable mirror arrays.更多还原