複合式近場記錄導光模組之研究

Study of Near-field Hybrid Recording Module

邱彥群(Yan Ching Chiu)

指導教授 ： 張明文 ； 劉宗平

元智大學/工程學院/電機工程學系/碩士(2003年)

摘要

目前磁光碟機所採用光寫光讀記錄之光點大小約為記錄50nm，讀取200nm；但均因為受限於光束繞射極限與碟片基板入射型讀取方式，所以無法使用高數值孔徑物鏡進行讀寫動作，解決之道必須改以近場光學記錄模式。而多數近場光學記錄之研究方向又以固態浸沒式透鏡搭配飛行光學讀取頭來替代傳統光學讀取頭。於是我們便結合近場和波導之原理搭配導光透鏡（準直透鏡、聚焦物鏡、SIL）於光波導基板上，利用微機電製程技術直接以光罩垂直蝕刻所有導光元件，即形成所謂的導光模組。由於以MEMS技術製作之導光模組體積小且質量輕，可置放於飛行頭上，以近距離貼近碟片做近場光學記錄，若再能搭配GMR磁性讀取頭，完成複合式近場記錄方式，將可大量提升資料讀取密度。
在本論文中，首先將針對所欲設計之導光模組作波導原理分析，解得一相關特徵方程式，之後便利用光學設計軟體(ZEMAX)和光束傳播法(BPM-CAD)分別模擬在導光模組中所產生的光學特性，並使用光罩微影蝕刻技術製作導光模組結構，最後針對導光模組設計一套完整精密量測之實驗架構。經實驗結果得知所設計之導光模組確實有聚焦收斂之效果。

關鍵字

近場記錄 ； 波導 ； 光學讀寫頭 ； 光束傳播法 ； 光學設計

並列摘要

Most of the magneto-optical disk drives use optical reading/writing record methods, which make record read 50nm/write 200nm optical spot. The optical diffraction limit and the basic substrate-incidence recording technique, all have restriction on the using of high numerical aperture objective lens unless they use near-field recording. Traditional optical pick-up head is replaced by flying head combined with solid immersion lens in the last optical near-field researches. We studied the near-field optics and the fundamentals of optical waveguide device to achieve waveguide hybrid advanced MEMS (WHAM) by using photo lithographic method. Use the MEMS technical method to fabricate WHAM can make the module small size and light weight, so as it could be put in flying head to fly near the disk to achieve near-field recording. Once the WHAM module can be combined with GMR head to realize optical hybrid recording method, data storage density could be well increased.
In this thesis, we aimed to analyze optical waveguide theory and solve the fixed eigenvalue equation of our desired WHAM module. We do the simulation of the optical characteristics in WHAM module by used optical design softwares ‘ZEMAX’ and ‘BPM-CAD’ before fabrication by using of photo lithographic technique. Finally we measure all the characteristics completely of the WHAM module, its precision experimental setup was designed ourselves. From experimental result, our WHAM module really produces good focus and convergence.

並列關鍵字

Near-field Recording ； Waveguide ； Optical Pickup Head ； Beam Propagation Method ； Optical Design

參考文獻

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