利用積分法與諧波分析於增益調製半導體雷射二極體 之時序跳動特性比較

Abstract

兩種有關於增益調製的雷射二極體之時序跳動特性的方法將被實現比較於理論和實驗。積分法使用了單邊帶(SSB)相位雜訊頻譜的頻譜面積來計算方均根(rms)的時序跳動。另一種方法，諧波分析，則是利用高次諧波的最高雜訊功率來得到時序跳動。儘管這兩種方法皆被證實是準確的，但是還沒有人做過其完整的比較。本論文首先展現出強度雜訊和時序跳動皆可藉著把兩種方法實現於Labview程式來有效地被特性化。結果表現出積分法(1.1ps)和諧波分析法(1.25ps)得到一致的時序跳動值於擁有外腔的增益調製雷射二極體。此兩種方法也被比較討論於二極體增益的Yb:KY(WO4)2 (Yb:KYW)被動鎖模雷射雜訊量測且都得到2ps的方均根時序跳動值。此結果表示無論是諧波分析法或積分法皆可以成功地用來計算時序跳動。

A theoretical and experimental comparison between two methods of timing jitter calculation in the gain-switched laser diode is made. The integral method utilizes spectral area of the single side-band (SSB) phase noise spectrum to calculate root mean square (rms) timing jitter. Another approach, harmonic analysis, exploits the uppermost noise power in high harmonics to retrieve timing fluctuation instead. Even though both methods have been verified to be accurate, a full comparison has yet to be performed. This thesis will first demonstrate that both amplitude noise and timing jitter fluctuation can be characterized efficiently by implementing two methods with Labview programs. Results show that a consistent timing jitter is found by the integral method (1.1ps) and harmonic analysis (1.25ps) in gain-switched laser diodes with an external cavity scheme. A comparison of the two approaches in noise measurement of diode-pumped Yb:KY(WO4)2 (Yb:KYW) passive mode-locked laser is also discussed, which both give an outcome of 2ps rms timing jitter. The results indicate that either harmonic analysis or integral method can be successfully utilized to calculate timing jitter.