Single-stage Erbium-doped Fiber Amplifier Research Articles

A Comparative Study and Radial Performance Evaluation for Reflective EDFA Configurations with Optimized Intrinsic Parameter Sets

For the improvement of Gain and Reduction in Noise Figure, a range of Erbium Doped Fiber Amplifier (EDFA) based configurations from simple Single Pass (SP) EDFA to Quadruple Pass with Filter (QPF) EDFA have been investigated. Modified Giles model for rate and propagation equations has been proposed and subsequently used for Gain and Noise Figure evaluation for all configurations. The influence of EDFA based configurations on its internal design parameters is investigated to obtain an optimum design parameter set. Among the single stage EDFA configurations, Reflective Double pass with Filter (DPF) with a high optimum Numerical Aperture gives good radial performance with high signal overlap factor of 0.563 and Pump overlap factor of 0.834. For the dual stage configurations, second stage of Reflective QPF EDFA gives best signal overlap of 0.6727 and pump overlap of 0.8827, whereas it has the lowest pump threshold of 0.47 mW, hence highest pumping efficiency. At 1550 nm of input signal wavelength, maximum gain of 27.66 dB and low Noise figure of 5.4 dB was obtained in QPF EDFA at lowest pump power of 20 mW. Thus QPF EDFA is suitable choice for preamplifier applications at 1550 nm.

Analytical formula for the transient response of erbium-doped fiber amplifiers

In wavelength-division-multiplexing systems with optical amplifiers, channel drop or add can cause power changes in the existing channels. We present an analytical formula for the transient power of the existing channels as a function of time when one or more input channel is dropped or added on an erbium-doped fiber amplifier (EDFA). Although this formula was originally derived from perturbation theory of single-stage EDFA's, it is a good approximation of large-power excursion cases as well as two-stage EDFA's.