查詢結果分析
來源資料
頁籤選單縮合
題 名 | The Analysis & Recongnition between Noise and Chaos on the Laser System=雷射系統中雜訊和混沌現象之間的分析和辨別及其應用 |
---|---|
作 者 | 蕭進松; | 書刊名 | 樹德學報 |
卷 期 | 24 1999.08[民88.08] |
頁 次 | 頁119-131 |
分類號 | 448.5 |
關鍵詞 | 脈衝擺動; 加成脈衝; 混沌現象; 奇值分解法; 特徵值頻譜; Fluctuations; Additive-pulse; Chaos; Singular value decomposition; SVD; Eigenvalue spectrum; |
語 文 | 英文(English) |
中文摘要 | 在克爾透鏡鎖模藍寶石雷射的脈衝裡,次諧波振盪包含雷射光束空間調變週期2(圖 1),週期3(圖2)和近週期。在連續波鎖模雷射中已有脈衝擺動的理論說明。不同型式的 雜訊,如脈衝能量、脈衝重複時間、脈衝間隔的擺動,可以從它們的頻譜特性很容易辨識得 到。 加成脈衝鎖模雷射顯示各種不穩定現象,其中最常遇到的是光纖中有非線性效應。若加 成脈衝鎖模雷射有非線性及延時回饋現象,則希望它會有動態現象,甚至會衍變成混沌現象 (圖3)。 給予一個純量時間級數,奇值分解法(SVD)可將系統的軌跡矩陣之特徵值頻譜導出 來,此SVD特徵值頻譜可被用來測試混沌及估計雜訊強度。 以混沌雷射作通訊上的使用是可行的,將微小訊號嵌入大的混沌載波中並傳輸到接收系 統,然後從混沌訊號取回此微小訊號,混沌光波因此能被用在寬頻保密訊息的通訊裡。 |
英文摘要 | Subharmonic oscillations in the pulse train of a kerr-lens mode-locked Ti: sapphire lasers including period doubling (Fig1), and period 3 (Fig2), and quasi periodicity, theoretical investigation of the fluctuations of the pulses from continuous wave mode-locked lasers is presented. Different type of noise such as fluctuations of the pulse energy, pulse repetition time, and pulse duration, can be readily recognized from their characheristic spectral signature. Additive-pulse mode-locked (APM) lasers exhibit a variety of instabilities. Among the most frequently encountered are the effects of excessive nonlinearity in the fiber. Given that AMP lasers contain nonlinearity and time-delayed feed back, we would expect that it would be capable of complex dynamics, including chaos and the well-known routes to chaos (Fig3). Given a scalar time series, the method of singular value decomposition (SVD) can derive the eigenvalue spectrum of could be utilized to test the chaos and estimate the strength of noise in time series. Communication with chaotic lasers has been possible. A small message was embedded in the larger chaotic carrier and transmitted to a receiver system where the message was recovered from the chaos. Chaotic optical waveform can thus be used to communicate masked information at high band widths. |
本系統中英文摘要資訊取自各篇刊載內容。