跳到主要內容

臺灣博碩士論文加值系統

(44.210.85.190) 您好!臺灣時間:2022/11/30 00:51
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果 :::

詳目顯示

我願授權國圖
: 
twitterline
研究生:向華埏
研究生(外文):Shiahng, Hua-Yan
論文名稱:受激布里淵散射相位共軛鏡之反射及脈衝壓縮性質
論文名稱(外文):Reflection and Pulse Compression Properties of SBS phase Conjugate Mirros
指導教授:唐建堯
指導教授(外文):Tang, Chen-Yau
學位類別:碩士
校院名稱:淡江大學
系所名稱:物理學系
學門:自然科學學門
學類:物理學類
論文種類:學術論文
論文出版年:1997
畢業學年度:85
語文別:中文
論文頁數:57
外文關鍵詞:stimulated Brillouin scatteringphase-conjugate mirros
相關次數:
  • 被引用被引用:1
  • 點閱點閱:131
  • 評分評分:
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
本論文之主要目的是探討受激布里淵散射(stimulated Brillouin scattering, SBS)相位共軛鏡的反射及脈衝壓縮性質,並假設準穩態條件來研究SBS反射的基本原理並和實驗作比較。我們在實驗中使用一單模Q開關Nd-YAG雷射,其脈衝能量約為數毫焦耳,時寬約為11ns;雷射光經一透鏡聚焦於SBS介質中而產生反射。實驗顯示入射脈衝之能量為SBS反射之重要參數;它對能量反射率、反射脈波之時間寬度有顯著之影響。聚焦透鏡焦距之長短對SBS反射亦有顯著影響:聚焦較強時得到較高的反射率,然而在較弱聚焦條件下脈衝壓縮效應卻較強。SBS反射率及能量閥值與聚焦透鏡至SBS室之間的距離有關。我們發現當此相對距離在一定範圍內變動時,脈衝能量反射率變化不大,然而,脈衝時寬卻可顯著改變;短焦距聚焦的情況下,反射閾值沒有顯著變化,但在長焦距聚焦的情況下,反射閾值略微上升;推算有效作用區長度約為Rayleigh range的4倍。我們研究以SBS共軛組成之自注式共振腔的輸出特性,發現共軛鏡反射可維持原光束之空間品質,並藉光譜分析推算四氮化鍺的布里淵頻移為2.2(±O.1)GHz,丙酮的布里淵頻移為2.9(±0.1)GHz;此外,運用反射閾值比較法,我們估計四氯化鍺的布里淵增益係數為 13 Cm/GW,這方法能提供一種測量SRS增益係數的簡單途徑。
The main purpose of this thesis is to investigate the reflection and pulse compression properties of stimulated Brillouin scattering (SBS) phase-conjugate mirrors, and the basic theory of SBS reflection was studied in the steady-state approximation. A single-mode Q-switched Nd-YAG laser was employed in our experiment; the laser pulse energy was of a few mJ and the pulse duration was about 11 ns. The SBS reflection was achieved by focusing the laser beam into a cell filled with SBS medium. Our experiment shows that the incident pulse energy is an important parameter in SBS reflection; it affect the energy reflectivity and the pulse duration of the reflected pulse in a significant way. The focal length of the focusing lens also plays an important role: higher energy reflectivity may be obtained with shorter focal lengths, while stronger pulse compression effect may occur with longer focal lengths. The SBS reflectivity and threshold energy may vary with the distance between the focal lens and the SBS cell. We found that the reflectivity may remain essentially constant when the relative distance is varied over a certain range, while the duration of the reflected pulse may change significantly; the SBS threshold energy may remain the same for shorter focal lengths, but it may raise slightly when the focal length gets too long; and that the effective SBS interaction length is about four times the Rayieigh range. A self-injected oscillator was formed by placing an SBS mirror near one end of the laser cavity, and the spatial quality of the output pulses remained nearly the same with or without the SBS mirror. Spectral analysis showed that the Brillouin shift is 2.2 GHz in GeCl4 and 2.9 GHz inacetone. The SBS gain factor of GeCl4 was estimated to be around 13 cm/GW by a simple comparison method.
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top