臺灣博碩士論文加值系統

光學量測技術隨著雷射技術的長足進步，使得與光相位有關的訊息得以量測，在本論文中，我們結合了超快光學與干涉儀的技術，達到高相位鑑別率光學量測系統，將超短脈衝雷射耦合至光纖內產生頻變式脈衝雷射，以此頻變脈衝雷射作為馬赫仕德干涉儀的光源，頻變脈衝干涉的結果，將已往解析光相位約方法，由光學領域轉至電的領域解析，可大幅提高馬赫仕德干涉儀於光相位變化的鑑別率。論文中討論了光相位變化與頻率變化的關係，我們以非線性薛丁格方程式分析了超短脈衝在光纖中產生頻變的情形，並以此頻變式光脈衝分析其應用在馬赫仕德干涉儀時的狀況，此外對於本實驗系統雷射在脈衝寬度 20ps，輸入光纖平均功率為300mW，光纖長度為108m下能得到約 9.5dB 的差頻動態。

With the progress of the laser techniques in an optical measurement system, the signal about optical phase can be measured. In this thesis, we combined the techniques of ultrafast laser and interferometery to achieve high phase discrimination in an optical measurement system. We couple the ultrashort pulse laser into fiber to produce chirped pulse laser which serves as the source of a Mach-Zehnder interferometer. With this arrangement, we can not only transform the analysis of optical phase from optical domain to the electric domain but also highly enhance the discrimination of phase difference in Mach-Zehnder interferometer. In addition, we discuss the relation between optical phase variation and frequency variation, and analyze the condition of chirped ultrashort pulse laser in the fiber by nonlinear Schrodinger equation. With the coupling of a 20-ps pulse, 300-mW average power laser beam into an 108-m fiber, 9.5-dB frequency dynamic range can be achieved in this measurement system.