利用Fabry-Perot濾波器於接收端來改善光纖有線電視系統傳輸性能

Employing Fabry-Perot Etalon at the Receiving Site to Improve Fiber Optical CATV System Performance

廖家政(Chia-Cheng Liao)

指導教授 ： 呂海涵

國立臺北科技大學/電資學院/光電工程系研究所/碩士(2008年)

摘要

藉由1550 nm波段光纖傳輸，類比光纖有線電視傳輸系統已被廣泛運用，然而長距離傳輸仍受到光纖有線電系統性能參數值的限制，在本篇論文中，我們提出兩種光纖有線電視系統架構，利用分頻多工技術及Fabry-Perot 濾波器來有效地改善光纖有線電視系統性能參數值：載波雜訊比、載波二次合成拍差比與載波三次合成拍差比。
首先，我們提出並驗證一個以外部調變的方式傳送NTSC滿載77頻道光纖有線電視系統架構，整體系統經由三級摻餌光纖放大器及長距離100 km (40km + 40km + 20km) 單模光纖傳輸；我們利用Fabry-Perot 濾波器於接收端以抑制長距離傳輸導致光纖色散問題，和傳統傳輸100公里單模光纖的外部調變式的光纖有線電視系統相比較，我們提出系統架構可以獲得較佳的載波雜訊比、載波二次合成拍差比與載波三次合成拍差比。
最後，我們提出分頻多工技術建構在直接調變方式傳送NTSC滿載77頻道光纖有線電視系統架構，經由三級摻餌光纖放大器及100 km單模光纖傳輸；我們證明同時利用分頻多工技術於發射端及Fabry-Perot濾波器於接收端可有效減少雷射光譜線寬，改善由光纖色散所造成的系統參數劣化，提升系統的傳輸參數值。

關鍵字

直接調變 ； 外部調變 ； Fabry-Perot 濾波器 ； 分頻多工技術 ； 光纖有線電視

並列摘要

Analog fiber optical CATV transmission systems have recently been enhanced by the introduction of 1550nm technology. However, the maximum transmission distance of fiber optical CATV systems is limited by RF parameters. In this thesis, we proposed two kinds of fiber optical CATV systems. Using split-band technique and Fabry-Perot etalon filter to improve carrier-to-noise ratio (CNR), composite second order (CSO) and composite triple beat (CTB) performances.
First of all, we proposed and demonstrated an externally modulated NTSC 77-channel full loaded fiber optical CATV transmission system. System link with three cascaded EDFAs and a transmission length of 100 km consisted of three SMF spans (40km + 40km + 20km). And we use FP etalon filter at receiving site to compensate long-haul fiber transmission causing fiber dispersion. Good performance of CNR, CSO and CTB were achieved in comparison with conventional externally modulated fiber optical CATV transport system over a 100 km SMF transmission.
Finally, our proposed NTSC 77-channel fully loading directly modulated transport systems employing split-band technique at the transmitting site. Over a 100 km SMF and amplifier using three stages of EDFAs. This study experimentally demonstrates simultaneous using split-band technique at the transmitting site and Fabry-Perot etalon filter at receiving site to compensate the fiber dispersion and to reduce the spectral linewidth. As a result, to take possession of the best all CATV RF parameters.

並列關鍵字

directly modulated ； externally modulated ； Fabry-Perot etalon ； split-band technique ； fiber optical cable television

參考文獻

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