我們希望利用微機電製程技術來作光學讀寫頭的微小化，並設計一種可變曲率的反射薄膜來達到讀寫頭高頻寬伺服的功能。我們假設微機電可變曲率反射薄膜能以頂點變形來形成一完美的球面反射鏡，則鏡面曲率的快速變化將可導致系統聚焦光點位置的即時改變，形成一種高頻的聚焦伺服。
本論文初步研究了三種光路設計：A法為以反射薄膜取代轉折平面鏡，光束為偏軸入射；B法為光路中加入平行板分光鏡使光束形成正軸入射；C法為加入立方體分光鏡使光束形成正軸入射。此三種設計分別以一階光追跡方程式推導其薄膜變形量與系統聚焦光點位置變化之關係，並利用光學模擬軟體作實際規格的聚焦光點品質分析。

最後我們得到三種光路所產生的聚焦光點位置改變量皆可利用來作碟片基板厚度變異的聚焦伺服。而聚焦光點品質除以反射薄膜取代轉折平面鏡法（A法）較差外，在光路中加入分光鏡的設計（B法、C法），光點品質均可達到繞射極限。

The accomplishments of this dissertation is designing and implementing a miniaturized optical pickup head that is capable for mass production by employing MEMS technology. The preliminary element designed in the pickup head system is a MEMS deformable reflective film providing a high-frequency servo in the optical storage system. The reflective film performs a perfect spherical mirror at different curvature by deforming its vertex. Hence, the different radius of curvature of the reflective mirror induces a quick change of the focal position of the optical pickup head, and serves as a focusing servo system. By controlling the deformable parameters, the servo system affords high frequency response that is capable for high speed optical storage..
We work out three designs of optical system: (A) replacing the folder mirror by the deformable film; (B) inserting a plate beam splitter into the optical path; (C) inserting a cube beam splitter into the optical path. The three designs were simulated for pickup head of optical storage system. Utilizing the ray tracing methods based on geometric optics retrieves the variations of the focal position corresponding to the displacements of film’s vertex. Next, the optical software-ZEMAX- simulates the profiles of the focal spot of the designed optical systems, and exam the diffraction-limited property of the focal spot.

In conclusion, the changes of focal position of the three designs are adequate for a focus servo of the variations of the disk substrate. The quality of focal spot is appropriate for the pickup head system in the design (B). and (C). However, the focal spot cannot perform the diffraction-limited quality in the design (A).

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