The Design And Realization Of Variable Angle Mechanism Of Muller Matrix Ellipsometer

Mueller matrix ellipsometer is an advanced optical measurement instrument, compared with conventional measuring instrument, it has the non-contact, no destructive, fast and the ability to acquire rich information, etc. The Muller matrix ellipsometer can achieve high precision measurement of Nano structure by incident angle, multi azimuth configuration optimization of measurement conditions, etc. Variable angle module is the key to achieve multi-angle measurement, and it acts as an important part of the instrument. The performance of variable angle module directly affects the measurement accuracy and precision of the instrument. This thesis focuses on the mechanical design and implementation of the variable angle module of Mueller matrix ellipsometer. The main work includes:Complete the analysis of different types of variable angle module based on the comparative analysis of the structure design of existing ellipsometer products on market, and summarize the advantages and disadvantages of each design. According to the actual requirements, scheme design of the variable angle module is determined. On the basis of the scheme, the motor is selected according to the input torque calculated based on the requirements.Based on the design scheme, parameter designs and 3D modellings of each part are completed. By using Pro/E Wildfire 4.0 software platform, these parts and components are virtually assembled, and interferences between components. In order to verify the feasibility of the design, we check the overall trajectory of mechanism, and analyze the simulation results for different curve angles, angular accelerations and loading conditions using the Pro/E simulation module.According to the finite element method, we carry out the static analysis for the key components of the variable angle module using ANSYS Workbench analysis software. Using the simulation results as the design inputs, weaknesses can be avoided. Additionally, we use modal analysis to study the vibration characteristics of the variable angle module.To verify the module performance metrics, we assemble and test the module. The actual arm rotation angle are measured, and the repeatability of short-term test is carried out. We comprehensively analyze the error sources of the variable angle module, and put forward the corresponding improvement methods.