Beat wave laser is a topic that has drawn a lot of attention recently, especially in the area of free electron laser and plasma-wave accelerator. Mode-locked laser source with femtosecond pulse width is commonly used to generate the phase-locked beat wave. However, in our experiment, we demonstrated the 813 nm beat wave generation through beat-wave seeded optical parametric amplification (OPA). The pump used in our experiment was 532 nm, while the nonlinear crystal was MgOLN. Stable comb-like sidebands are observed in the spectrum of the signal. The separation of the sidebands is tunable and determined by the beat frequency of the seeding. The large separation of the sidebands and tunable separation are the important advantages of beat-wave seeded OPA. We also simulated the behavior of the pulse during the optical parametric process. Through a proper walk-off time between the signal and the idler, a high pulse compression ratio can be achieved, and the needed crystal length is reduced by modulating the intensity of the seeding. Our simulation also explains the sidebands generation in beat wave seeded OPA but not in spatial dependent sidebands generation. This phenomenon is observed in another beat-wave seeded OPA. The pump in this experiment was 1064 nm, and the nonlinear crystal was the periodic poled lithium niobate (PPLN). We deduced that the spatial dependent sidebands generation may be caused by the divergence of the Gaussian beam and the phase match condition of the sideband. Future work on this experiment including the improvement of the conversion efficiency and photoconductive antenna will also be discussed.

拍頻雷射領域的應用最近這幾年受到很多的關注，特別是自由電子雷射和電漿加速器方面；而脈衝寬度只有千萬一分之一秒的鎖模雷射，是最常用來產生拍頻雷射的工具。在本實驗中，我們將兩種1.5微米左右的遠紅外光雷射耦合進同一光纖裡產生拍頻效應，再利用摻雜百分之五鎂的鈮酸鋰晶體和532奈米的綠光雷射，做光參數放大，產生813奈米左右的拍頻雷射。在實驗的結果方面，藉由調整兩道遠紅外光雷射的波長，我們成功的做出了頻率可調的拍頻雷射，並且觀察到明顯且穩定的梳狀旁帶信號；和一般鎖模雷射或拉曼散射產稱的旁帶信號比較，利用光參數放大產生旁帶信號主要的優點在於它產生的旁帶信號間距大且可調。從我們對光參數放大的模擬，發現到只要適當的控制光參數產生過程中，三種訊號之間群速度的分離效應和取適當的晶體長度，既可產生脈衝壓縮及功率放大的效應，並且若將光參數放大中種子訊號做強調變，我們可以大幅縮短所需的晶體長度而得到脈衝壓縮的效應。從1064奈米作泵浦，在週期性極化反轉的鈮酸鋰晶體中進行光參數放大的實驗結果中，我們發現波長在1064奈米的旁帶訊號與空間的相關性。在本論文的模擬中，可以觀察到旁帶訊號的產生，卻無法得知其與空間的相關性。我們對此題提出了一個解釋，認為這是由於旁帶訊號相位匹配的條件改變，和當為種子訊號所設計的有些微不同，因此我們能在發散的高斯束中觀察到旁帶訊號與空間的關聯性。在本論文的最後，我們介紹以後需要改進部份以及實驗成果的應用。

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