使用量子點雷射減慢光訊息行進速度

Abstract

本論文旨在探索半導體雷射於作為慢光元件之新穎用途。針對之前實驗所觀察量子點面射型雷射的慢光現象進行探討，並使用雷射放大器模型進行理論模擬。模擬結果解釋了光訊息速度隨著雷射增益加大而減慢，以及隨者調變頻率增高而加快等實驗上觀察到的現象。此外，針對實驗尚未研究的部份，模擬結果預測了1至5 GHz的光訊息在該雷射元件之行進速度。在另一方面，本論文從實驗的角度探索了使用半導體雷射外部注入光之技術來減慢光資訊速度之可能。利用網路分析儀所量測到的相位響應顯示有可能達成接近360度的RF訊號延遲。光譜資料顯示了這樣的RF延遲與光訊息被不對稱的放大有關。

This thesis explores the novel use of semiconductor lasers as optical delay lines. Slowing light using vertical-cavity surface-emitting lasers (VCSELs) is explained and simulated using the VCSEL amplifier model. Simulated results and experimental result are qualitatively in a good agreement. With the aid of the filter phase analysis, the simulations explain that group delay increases with increased modal gain and decreases with increased modulation frequency. Besides, the simulations predict the VCSEL’s capability of delaying single-tone sinusoidal signal of 1 to 5 GHz. On the other hand, RF delay or optical delay using injection-locking of VCSELs is studied experimentally in the thesis. Optical spectra show that the VCSEL is not in the stable-locking range. The VCSEL acts as a regenerative amplifier, making one of the signal side band much larger than the other.