非同步約分諧波鎖模掺鉺光纖光固子雷射之雷射動力學

Abstract

本論文主要探討非同步約分諧波鎖模□鉺光纖光固子雷射的雷射動力學特性，一方面透過約分諧波鎖模來達到超高重複率，也同時透過非同步鎖模來獲得良好的鎖模脈衝輸出。我們在實驗上進一步利用非同步鎖差頻的方式來補償共振腔的擾動，接著量測和探討整個雷射系統的雷射動力學。我們也利用RF頻譜的資訊計算出非同步約分諧波鎖模脈衝在時間上的變化和光頻的變化，利用這些結果去反推等效調變深度，並進一步驗證相位調變非同步約分諧波鎖模雷射的等效調變效應主要來源為RF放大器的高階分量。我們在探討雷射動力學的時候也發現了一個新的同步諧波鎖模雷射操作模態，可以產生重複率高達40GHz的穩定鎖模脈衝雷射並在RF頻譜觀察到邊頻項，透過設計一連串的實驗我們也探討了這個有趣新穎的新操作模態。

The thesis is focused on the laser dynamics studies of asynchronous rational harmonic mode-locked Er-doped fiber soliton lasers. The rational harmonic mode-locking can provide higher repetition rates and the asynchronous mode-locking can help achieve good mode-locking performance. We stabilize the laser cavity length by locking the deviation frequency of asynchronous mode-locking to help measure the laser dynamics of the laser system. Base on the information of the RF spectra, we estimate the timing and center frequency variation of the asynchronous rational harmonic mode-locked pulse trains. We verify that the effective modulation strength is mainly from the higher order signals of the RF amplifier in asynchronous rational harmonic mode-locked lasers with only phase modulation. We also experimentally find a new operation state of synchronous harmonic mode-locking. Stable 40 GHz mode-locking operation can be achieved with RF spectral sidebands quite similar to the asynchronous mode-locking. A series of experiments have been performed to investigate the characteristics of this interesting new operation state.