In this paper, a detailed model of a hybrid dual-stage Raman/erbium-doped fiber (EDF) amplifier is presented. This model takes into account the impact of double Rayleigh backscattering (DRB) noise, amplified spontaneous emission (ASE) noise and Kerr-nonlinearity induced impairments in the amplification process. Using this model, we present a comprehensive analysis of the operation of hybrid dual-stage Raman/EDF amplifiers under above impairments. We show that under fixed total gain conditions for the amplifier module, high Raman gain causes the introduction of increased DRB noise to the amplified signals whereas low Raman gain causes the introduction of high ASE noise power through EDF amplifier. Therefore a balance between the Raman amplifier gain and EDF amplifier gain is required for optimal operation. These observations are then combined to show an optimization process, which could be applied to improve the design of hybrid dual-stage Raman/EDF amplifiers.

This paper describes the impact of EDFAs on AM/FM FDM subcarrier multiplexing (SCM) all-fiber video distribution (AFVD) systems. As AM/FM hybrid system using EDFAs which can simultaneously distribute 11 AM-TV channels and 50 FM-TV channels is proposed and discussed. 4-stage amplifier-branch transmission experiments are introduced. The construction and performance of a newly designed 50 channel FM tuner are also presented.