外調式固態雷射光纖傳輸系統

Abstract

本論文研製之外調式固態雷射光纖傳輸系統，利用高功率低雜訊的固態雷 射加上壓控的調制器，做為傳輸系統的主要部份。實驗上製作穩壓電路及 線性化電路改善調制器本身的非線性，使60個AM- NTSC頻道經25公里光纖 ，CNR > 50dB 、CTB <-57dBc、CSO < -65 dBc。線性化電路使系統CTB可 改善12dB，全系統傳輸功率達10dB。 A high power Nd:YAG laser with a linearized external modulator is demonstrated for a transmission of 60 channel AM-NTSC video. The nonlinear of external modulator limit the performance of such a system .In this thesis ,we demonstrate a bias controller and a pre-distortion linearization technique which reduce the modulator generated third-order distortion products by 12 dB.When combined with the Nd:YAG laser ,the yield a 60-channel video system with 10 dB power budget for carrier-to-noise ratio of 50dB and com- posite distortion products ;CTB less than -57dBc and CSO less than -65dBc