建構分佈反饋式雷射其主模與-1側模之鎖模注入技術於光纖微波傳輸系統

Radio-over-Fiber Transport Systems Based On Distributed Feedback Laser Diode With Main and -1 Side Modes Injection-locked Technique

蕭宇超(Yu-Chao Hsiao)

指導教授 ： 曾世杰

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2009年)

摘要

在本篇論文主旨在研究與設計不同種類型態之光纖通訊傳輸系統，而所提出與經由實驗證實之不同種類的傳輸架構，其中包含有類比與數位傳輸系統、光纖微波傳輸系統及全雙工光纖微波傳輸系統，建構於不同的傳輸技術，如鎖模注入技術、直接調變與外部調變、僅一光單旁波帶調變技術等，進而改善側模抑制比與色散之影響，達到提升整體傳輸系統效能之改善。
首先，利用法布里-珀羅雷射二極體(Fabry-Perot Laser Diode, FP LD)其具有較佳之成本效應與多重模態之特性，藉由二顆法布里-珀羅雷射二極體互相鎖模注入技術，獲得一平坦且多模態的光頻譜，因而獲得一寬頻光源，且提供一顯著優異之機制，取代需要使用一昂貴之外部調變器與載波抑制技術的架構，大幅降低系統成本與簡化。
其次，利用僅一光單旁波帶調變技術，藉由光單旁波帶的方式，可以縮減線寬，大幅改善傳輸時所導致色散之影響，因而降低射頻功率衰減的情形，且使用分波多工(Wavelength Division Multiplexing, WDM)及光塞取多工(Optical Add-Drop Multiplexers, OADM)技術可以簡化系統架構及方便基地台的升級作業。
再者，利用分佈反饋式雷射二極體之-1模鎖模注入技術，以直接調變方式混合基頻(622Mbps)與射頻(622Mbps/10GHz)訊號，根據先前所進行之研究，習得由光電子回授技術，可以大幅提升光功率，進行傳輸80公里標準單模光纖，即建構一同時具有光纖到家(數位基頻訊號傳輸)與光纖微波傳輸之整合型傳輸系統。
最後，利用主模及-1側模之鎖模注入技術，達到提升分佈反饋式雷射二極體(Distributed Feedback Laser Diode, DFB LD)之本身頻率響應，且提高側模抑制比，因此技術可以將任一選定之側模形成光源，取得全新多根光源，以直接調變方式，且在用戶端不外加任何光源，建構一傳輸光源於中心機房之網路，進行光纖微波傳輸，經下行傳輸40公里與上行傳輸80公里標準單模光纖，獲得優異之誤碼率與傳輸效能提昇。

關鍵字

分佈反饋式雷射二極體 ； 鎖模注入技術 ； 光纖微波 ； 側模抑制比 ； 全雙工

並列摘要

In this thesis, we study various structures of optical fiber communication transport systems. The proposed transmission systems which are demonstrated include transport systems of analog and digital as well as transport systems of Radio-over-Fiber (ROF) and Full-duplex Radio-over-Fiber. The different schemes of transmission are engineered according to different techniques such as injection-locked technique, direct modulation, external modulation, and single sideband modulation in order to enhance side-mode suppression ratio (SMSR) and reduce dispersion. Therefore, the overall performance and configuration of transmission are extremely improved
First, employing mutually injection-locked Fabry-Perot (FP) Laser Diodes which possesses superior cost-effective benefits and multi-modes characteristics can achieve the flat and multi-modes spectrum. Accordingly, a broadband light source is obtained. Besides, it reveals an outstanding alternative with advantages in simplicity and cost instead of using expensive external modulators and sophisticated optical carrier suppression technique.
Second, employing only one optical sideband modulation technique greatly reduced the dispersion because it effectively diminished the linewidth so as to decrease radio frequency (RF) fading effect. Furthermore, it is convenient and beneficial for the systems and base stations to simplify and upgrade architectures through wavelength division multiplexing (WDM) and optical add-drop multiplexers (OADM) techniques.
Third, employing the -1 side mode of distributed feedback (DFB) laser diode injection-locked technique and optoelectronic feedback technique extremely raises SMSR and optical power according to the extension of previous studies and researches. Consequently, the baseband (622Mbps) signal and the RF (622Mbps/10GHz) signal are successfully transmitted simultaneously over an-80 km single mode fiber (SMF). Hence, it integrates the transport systems of fiber-to-the-home (FTTH) and ROF.
Finally, employing main and -1 side modes of DFB LD injection-locked technique according to the extension of previous studies and researches not only significantly increases the resonance frequency of the slave laser, but also prominently enhances SMSR. Moreover, any chosen side modes can be transmission light sources which provide several light sources to transmit. In addition, the system based on these techniques in direct modulation can transmit over a-40km SMF for the downstream and an-80km SMF for the upstream without any other light source in base stations. Good performances of bit error rate (BER) was achieved and improved. Therefore, a state-of-the-art lightwave centralized network is realized.

並列關鍵字

Distributed Feedback (DFB) laser diode ； Injection-locked technique ； Radio-over-fiber ； Side-mode suppression ratio (SMSR) ； full-duplex

參考文獻

[9] Y. C. Chi, “Hybrid Wavelength-Division-Multiplexing Transport System,” National Taipei University of Technology, 2007.

[1] K. G. Coffman and A. M. Odlyzko, Internet growth: Is there a “Moore’s Law” for data traffic, Handbook of Massive Data Sets, Kluwer, 2001.

[2] P. C. Won, and J. A. R.Williams, “Third-order intermodulation products generated on transmission through nonlinear radio-on-fibre link,” Electron. Lett., vol.40, pp. 1290-1291, 2004.

[3] M. G. Larrode, A. M. Koonen, J. J. V. Olmos, and A. Ng’Oma, “Bidirectional radio-over-fiber link employing optical frequency multiplication,” IEEE Photon. Technol. Lett., vol. 18, pp. 241-243, 2006.

[4] J. Capmany, “Multiwavelength single sideband modulation for WDM radio-over-fiber systems using a fiber grating array tandem device,” IEEE Photon.Technol. Lett., vol. 17 , pp. 471-473, 2005.