利用Fabry-Pérot雷射二極體產生波長可調脈衝雷射

Abstract

本論文的第一部份首先提出Fabry-Pérot雷射二極體自我注入之線性共振腔架構。利用在共振腔加入可調帶通濾波器，可以輕易產生波長可調脈衝雷射。由於共振腔長與雷射調變頻率有關，固定的共振腔長使得系統的可調範圍無法再提升。為了在不同波長維持固定的調變頻率以及脈衝寬度，我們提出Fabry-Pérot雷射二極體自我注入之環狀共振腔架構。利用在共振腔內加入光延遲器來控制共振腔長。在2000MHz的調變下，系統的可調波長達到46nm、旁模抑制比超過33.5dB，脈衝寬度也可以維持在45ps附近。

在本論文第二部份提出非常簡單之架構。利用Pabry-Pérot雷射二極體、可調濾波器以及摻鉺光纖放大器等三個元件產生脈衝訊號。利用可調濾波器作為系統波長選擇。而摻鉺光纖放大器的放大器自發輻射作為外部光源注入Fabry-Pérot雷射二極體，同時Fabry-Pérot雷射二極體產生的脈衝訊號還可以利用摻鉺光纖放大器進行放大。在2000 MHz的調變下，系統的可調波長達到34.5nm、旁模抑制比超過32dB，脈衝寬度則介於49.3ps-65.3ps。

In the first part of the thesis, a self-seeded Fabry-Pérot laser diode (FP-LD) using a linear-cavity scheme is demonstrated. By adding a tunable filter within the linear-cavity, the wavelength-tunable laser is easy to be tuned flexibly. Because the repetition frequency of self-seeded FP-LD is determined by the cavity length, this scheme is difficult to have widely wavelength-tunable range. Moreover, in order to maintain a constant repetition frequency and pulsewidth at different wavelengths, a self-seeded FP-LD using a ring-cavity scheme with a variable optical delay line is also presented. The wavelength-tunable range of this ring-cavity scheme is over 46 nm with SMSR up to 33.5dB. Furthermore, the pulsewidth maintain around 45ps at a constant repetition frequency of 2000MHz.

In the second part, an external injection scheme to generate wavelength-tunable optical pulses using a FP-LD is proposed and demonstrated. An Erbium doped fiber amplifier is used as both an external injection light source and an amplifier for the FP-LD. The wavelength-tunable range is over 34.5nm with SMSR up to 32dB. Furthermore, the pulsewidth is between 49.3ps-65.3ps at a constant repetition frequency of 2000MHz.