半導體雷射受光回饋擾動下之非線性動態特性與其應用

Characteristics and Applications of Nonlinear Dynamics Generated by Semiconductor Lasers Subject to Optical Feedback

林律志(Lyu-Chih Lin)

指導教授 ： 林凡異

國立清華大學/電機資訊學院/光電工程研究所/博士(2017年)

摘要

本論文主要是研究光回饋半導體雷射的動態特性與應用。當光回饋到半導體雷射時，將影響其載子濃度與雷射共振腔內折射率，產生頻率推移效應(frequency pushing effect)且改變其共振腔頻率(cavity resonant frequency)。調整光回饋強度以及外部共振腔長可以讓半導體雷射的出光有著豐富的非線性動態，像是混沌態(chaos, C)、類週期振盪態(quasi-periodic, QP)、週期一振盪態(period-one, P1)、規律脈衝(regular pulsing, RP)、低頻擾動態(low frequency fluctuation, LFF)等。本論文主要分為四個部分，第一部分我們介紹半導體雷射受到不同干擾方式產生非線性動態，且著重於光回饋半導體雷射的研究。第二部分將週期一非線性動態成功應用於一新穎雙頻都普勒雷射測速儀上，除具斑點雜訊抑制、高解析度外並同時擁有辨別物體方向之能力。由於其高解析的關鍵在於產生穩定且低線寬的週期一振盪態作為光源，且為了取代厚重且昂貴的微波訊號產生器，於第三部分中，我們根據量化穩定度的參數，研究且比較了光注入與光回饋量子井半導體雷射隨著不同條件所產生的週期一振盪態的線寬以及穩定度。此外，由於量子點雷射擁有比量子井雷射較低的相對強度雜訊(relative intensity noise)以及較好的溫度穩定性(temperature sensitivity)，相信產生的週期振盪態可以更穩定，於第四部分中我們研究了光回饋量子點多模半導體雷射分別單一激發基態與激發態，並分析隨著不同光回饋條件產生的動態特性，同時比較了脈衝封包頻率隨著不同外部腔長的變化，以及畫出雷射隨著不同光回饋參數的動態分佈圖。

關鍵字

半導體雷射 ； 光回饋 ； 非線性動態 ； 雷射穩定度

並列摘要

We investigate the characteristics and applications of nonlinear dynamics generated by semiconductor lasers subject to optical feedback. The optical feedback perturbs the carrier and the refractive index in the laser cavity shifting the cavity resonant frequency. Rich dynamics such as chaos (C), quasi-periodic (QP), period-one (P1), regular pulse package (RPP), and low frequency fluctuation (LFF) can be generated. In the first part of this dissertation, we introduce the nonlinear dynamics generated by semiconductor lasers subject to different perturbations and focus on the optical feedback dynamics. Next, we discuss the P1 oscillation and utilize it as the light source in developing a self-mixing dual-frequency laser Doppler velocimeter (SM DF-LDV) capable of the speckle noise reduction and the coherence enhancement. For improving the velocity resolution and replacing the bulky and costly microwave signal generator, in the second part, we compare linewidths and stabilities of the P1 oscillations generated by optical injection (OI) and optical feedback (OF). In addition, quantum dot lasers possessing low relative intensity noise (RIN) and low temperature sensitivity are very different from the quantum well (QW) lasers. They are expected to generate more stable periodic oscillation. In the fourth part, we investigate the dynamical states and their spectral characteristics of the optical feedback multimode quantum dot (QD) semiconductor lasers emitting exclusively on sole ground state and excited state.

並列關鍵字

Semiconductor laser ； optical feedback ； Nonlinear dynamic ； Laser stability

參考文獻

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