VISIBLE LIGHT COMMUNICAITION Enhancing Optical Signal-to-Noise Ratio in Terrestrial Cascaded EDFAs Fiber Optic Communication Links using Hybrid Fiber Amplifier Outline Abstract of the paper Introduction Calculating models Buiding algorithm charts Numerical Results and analysis Conclusion Abstract of the paper  Calculating models of Terrestrial DWDM cascaded EDFAs Fiber Optic Communication Links using Hybird Fiber Amplifier (HFA)  Build algorithm charts  Algorithm-based numerical calculating (MathCAD program) is applied in typical system  Optimized results show that the OSNR can be increased by (1-5)dB INTRODUCTION • • Hybrid Fiber Amplifier (HFA) is combination of Distributed Raman Amplifier (DRA) and EDFA Many WDM cascaded EDFAs systems using HFA have been investigated, experimented and deployed in order to get better OSNR CALCULATING MODELS • Calculating model consisting only one HFA if distance of Terrestrial WDM cascaded EDFAs Fiber Optic Comminication Link is shorter than 1,000km • Three typical calculating models are given in which HFAs are located in the first span, middle span and last span respectively CALCULATING MODELS CALCULATING MODELS • Calculating model of HFA with Backward pump at 1450nm • Optical Signal-to-Noise Ratio (OSNR) at the end of transmission link CALCULATING MODELS • Signal power at the end of link • FWM noise at the end of link • Accumulated ASE noise at the end of link BUIDING ALGORITHM CHARTS • Algorithm chart for calculating FWM noise power BUIDING ALGORITHM CHARTS • Algorithm chart for calculating ASE noise power BUIDING ALGORITHM CHARTS • Main algorithm chart for optimizing OSNR BUIDING ALGORITHM CHARTS • • Applying in the Vietnam Nation-wide DWDM system for optimization OSNR Vinh-Danang segment with HFA located in the first span; Optimized values: G1, G2 … G6,;Pin/ch ; OSNR are presented in Italic and Bold styles NUMERICAL RESULTS AND ANALYSIS • Choose wavelengths in this calculation are similar to that in realistic link • Non-Optimized and Optimized Gain of EDFAs in Vinh-Danang Link NUMERICAL RESULTS AND ANALYSIS • Signal and different noise powers at the end of 4-channel Vinh-Danang Link in cases of optimized and non-optimized parameters NUMERICAL RESULTS AND ANALYSIS • Non-Optimized OSNR at the end of Vinh-Danang link NUMERICAL RESULTS AND ANALYSIS • Non-Optimized OSNR (measured realistic results) and Optimized OSNR at the end of Vinh-Danang Link (MathCAD program) NUMERICAL RESULTS AND ANALYSIS • Signal and different noise powers at the end of 16-channel Vinh-Danang Link in cases of optimized and non-optimized parameters NUMERICAL RESULTS AND ANALYSIS • Optimized OSNR versus ordinal number of channels at the end of 16-channel Vinh-Danang Link NUMERICAL RESULTS AND ANALYSIS • Signal and different noise powers at the end of 32-channel Vinh-Danang Link in cases of optimized and non-optimized parameters NUMERICAL RESULTS AND ANALYSIS • Optimized OSNR versus ordinal number of channels at the end of 32-channel Vinh-Danang Link CONCLUSION • We proposed three calculating models of Terrestrial cascaded EDFAs Fiber Optic Communication Links using HFA • We built then algorithm charts for calculating FWM noise power, accumulated ASE noise power and for optimizing OSNR at the end of link in general case • Numerical calculating was applied in typical system (WDM Nation-wide Links in Vietnam) to get higher OSNR by (1-5)dB comparing with that in cases of parameters chosen by experience way Thank you ... CALCULATING MODELS • Calculating model consisting only one HFA if distance of Terrestrial WDM cascaded EDFAs Fiber Optic Comminication Link is shorter than 1,000km • Three typical calculating models... calculating models are given in which HFAs are located in the first span, middle span and last span respectively CALCULATING MODELS CALCULATING MODELS • Calculating model of HFA with Backward pump at 1450nm... CONCLUSION • We proposed three calculating models of Terrestrial cascaded EDFAs Fiber Optic Communication Links using HFA • We built then algorithm charts for calculating FWM noise power, accumulated