以飛行光學讀寫頭量測表面入射型相變化光碟片的記錄特性

Abstract

目前有關可讀寫光碟的研究中，不論是磁光碟片或 相變化光碟片，大部份皆是採取雷射光由基板入射 的讀 寫方式。其缺點在於光學讀寫頭設計複雜而重 量太大， 以致換軌動作太慢，因而限制其搜尋速度 。本文將探討 的飛行光學讀寫頭，是在滑片上嵌入 高光學數值孔徑的 物鏡，以約一毫米的高度飛行於 表面入射型相變化光碟 片的介電層表面上。雷射光 經由物鏡聚焦從表面入射， 進行資料的讀寫。此種 讀寫機制的優點在於不需要聚焦 伺服的裝置，因此 可簡化光學讀寫頭的設計，使得重量 減輕，進一步 提高的搜尋速度與記錄密度。在這篇論文 中，先以 程式模擬碟片結構與溫度分佈的關係，配合反 射率 模擬分析，設計出表面入射型的相變化光碟片。再 以動態量測結果與模擬預測比較，藉此探討飛行光 學讀 寫頭對表面入射型相變化光碟片的記錄特性。 Most of the optical recording products today use substrate incident recording. Because the complex design of the conventional optical head, it's hard to reduce the mass and improve the seek performance. The flying optical head that has been developed in this paper is an air bearing slider with a high numerical aperture objective lens. The flying height between the slider and the overcoat of the air incident phase change disk is about 1 micronmeter. A laser beam illuminates through the thin film surface and focuses on the active layer by the objective lens. The advantages of air incident recording are to eliminate the focusing servo and to reduce the size of optical head. One can design a much lighter and more compact optical head to achieve faster seek time and enable higher transfer rate. In this paper, We designed the air incident phase change disks according to the temperature distribution and reflectivity simulation results. Then we prepared phase change disks to perform the dynamic read/write test and discussed recording characteristics of air incident phase change disk using flying head.