非同步鎖模摻鉺光纖雷射參數可調特性之研究

Abstract

本論文主要研討非同步鎖模摻鉺光纖雷射之參數可調特性。在混合式主被動諧波鎖模機制的雷射實驗架構中﹐藉由雷射參數的改變，以RF頻譜分析儀上所獲得的數據為主，OSA光譜分析儀上所獲得的資訊為輔，來深入了解同步／非同步鎖模轉換與調變強度、調變頻率等雷射參數之間的關係，另一方面也利用變分推導與數值分析的方式來模擬同步區間到非同步區間的過渡變化。 在實際實驗上，雷射相位調變器的操作頻率為10GHz與20GHz，我們在此二頻率附近來作調變頻率之改變以及調變強度之改變，觀察的重點主要是諧頻的變化以及同步／非同步區間邊界的雷射操作狀態。透過光譜與頻譜分析儀之量測結果，我們發現10GHz和20GHz的操作態有稍微不同之雷射特性呈現。經由實驗的結果，我們驗證了同步／非同步鎖模區間之轉換邊界與雷射參數的關係，並能與基於變分法的理論結果來作比較。

The thesis is focused on the study of the tuning characteristics for asynchronous mode-locked Er-doped fiber lasers. With the experimental laser structure of hybrid active/passive mode-locking, laser performance data under parameter tuning are collected by the RF spectrum and optical spectrum analyzer to understand the relationship among the synchronous/asynchronous mode-locking and the modulation intensity/frequency. We also use the variational method and numerical solution to study the transition between the synchronization and non-synchronization operation states. In the experiment, the phase modulator is operated with the modulation frequency around the 10GHz and 20GHz with different modulation strengths. The changes of the RF spectra and the transition from synchronization to non-synchronization are the main focuses of observation. The 10GHz and 20GHz operation states exhibit slightly different performance characteristics. We experimentally verify the synchronous/asynchronous laser transition properties and compare the experimental observations with the theoretical predictions based on the variational method.