Design & Fabrication Technique Of MEMS-DMs

When lights go through the atmosphere or some optical devices, the wave front of the light might be distorted by the uneven atmosphere and the defects of the optical devices. The purpose of this thesis derives from the demand of correction to the distortion, especially to those space applications. This thesis describes the key device, that is DMs (deformable mirrors), of the adaptive optics technique which was widely used in the application for outer space. At first, we analyze the electrostatic force formula and use it to calculate the transform of our deformable mirrors model, then the finite element method which is developed rapidly in recent years to solve the problems of abnormity shape is adopted to emulate the structure of deformable mirror to get the size of every parts of the mirror in detail. The process of the emulation and those sizes of the DMs will be described in chapter 3. From the most important chapter 4, the design and fabrication of a novel deformable mirror based on the MEMS technology is presented in details to meet the requirement of DMs of less weight, less volume and less cost. At last a deformable mirror with 30×30 mm2 effective reflecting surface and 49 electrodes is fabricated successfully and the whole MEMS fabrication process is present in chapter 5. The keys such as etching, bonding, and element separating of the fabrication were particular concerned. The measured results show that the relationship between the deflection of the mirror and the voltage applied agrees well with the simulation result.