臺灣博碩士論文加值系統

利用圓偏極化脈衝雷射對磁光材料進行超快磁光反轉是近年來磁性記錄領域重要的突破，各國研究團隊爭相研究其中未知物理，該領域的未來是被所有磁光記錄媒體廠商所期待。
主宰超快磁光材料寫入的機制在於反法拉第效應(Inverse Faraday Effect)的應用，利用圓偏極化超短脈衝雷射作用在磁光材料上，可對磁光材料進行資料寫入的動作。然而，反法拉第效應於瞬間的作用仍未被完整的了解，本論文即著重在藉由磁光效應的探測，並且以飛秒(femto-second)時間尺度解析其作用的瞬間過程，試圖了解超快磁化反轉瞬間過程物理知識。
在本論文中的第一章先簡介我們實驗室想研究超快磁化反轉領域的主因與優勢，並且介紹本實驗室的雷射系統以及磁光材料記錄媒體的發展現況與目前的瓶頸；第二章著重在磁光材料的介紹、以脈衝雷射對磁光材料進行超快磁化反轉目前的發展以及國外研究團隊目前對這種超快磁化翻轉學理上的研究成果；第三章主要是介紹我研究的方法，包括實驗架設、參數設定、磁光材料選取以及實驗中的一些技巧；第四章則是實驗成果的呈現，依照分析結果試著解釋我觀測到的現象。

Ultrafast magnetization switching is now promoting for a whole new magnetic recording mathod. The application of inverse Faraday effect leads the magnetic recording technique to a great advance. We can control the magnetization of the magneto-optical material by using a circularly polarized femto-second pulse laser. Including the reading process, the processes of recording are all-optical. It’s amazing to everyone.
My experimental purpose is to resolve the transient transitional process of the magnetization switching, so I use pump-probe time-resolved experiment to explore the not-well-known process. I use femto-second pulsed laser as my probing and pumping light source. The pulse durations of both beam lines are about 40 fs.
In this thesis, I review the history of magneto-optical material’s application and introduce the laser system I use to experiment in Chapter 1. In Chapter 2, I introduce the characteristic of magneto-optical material, show the concept of magnetization switching process, and describe the achievements of other groups in resolving the transient process of the ultrafast magnetization switching. In Chapter 3, I explain my experimental setup and my diagnostic systems in detail. In Chapter 4, I show my experimental results and give a general explanation of my data. In Chapter 5, the conclusion and the possibly future work are introduced.
 

目次
摘要
Abstract
1. 序論 1
1.1 發展超快磁性記錄材料的優勢 1
1.2 磁光記錄材料的發展歷史 3
1.3 一兆瓦雷射驅動光源 4
2. 超快磁化反轉概述 8
2.1 磁光材料的特性 8
2.2 超快磁化方向的反轉 10
2.3 超快磁化反轉瞬間作用解析 14
3. 實驗架設與診斷系統 17
3.1 磁光材料的選擇與特性 17
3.2 診斷系統 - 磁光效應 20
3.3 主要實驗架設 23
3.4 主要實驗參數設計 27
4. 實驗結果與分析 29
4.1 時間解析實驗結果 29
5. 結論與展望 34
參考文獻 35

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