Abstract
Because of the numerous advantages in MEMS, such as miniaturization and batch process, it is becoming popular to use MEMS as optical components. Micro-Electro-Mecha-Optical system (MEMOS), aiming at optical applications in MEMS, use bulk micromachining to fabricate deformable mirrors to conduct adaptive optics devices (AO), which is used to correct distorted wavefront resulting from air disturbance. The deformable mirror can also be applied to change focal length. This study uses surface micromachining to fabricate bilayer structures, which will concave up when sacrificial layer is removed because of thermal residual stress between layers. It can be used as a variable focusing mirror if bias voltage is applied. An application for dynamical vertical servo tracking in CD pickup is presented in this proposal. Two parts are done in the thesis including analysis and fabrication. Analysis is conducted by ANSYS and INTELLICAD, respectively, to simulate deformation after processing and under applying voltage. In real fabrication, the redesigned fan-shaped structure successfully curls into shell-shaped geometry while the original designed disk-shaped device will warp. The measured curvature is around 400mm. Experiment setups have been proposed in the thesis to measure the dynamic response and observe the focusing spot.