Three-stage erbium-doped fiber amplifier for wide dynamic range and low noise figure

Abstract

High-gain and low-noise erbium-doped fiber amplifiers (EDFAs) are required for applications to preamplifiers and inline amplifiers.1,2 For obtaining high gain with low noise, schemes using an interstage isolator in single pumped two-stage amplifiers have been demonstrated.2,3 These schemes also provide constant output signal power over a limited range of input signal powers called the dynamic range. However, there is a trade-off between dynamic range and noise figure (NF) because the NF and the dynamic range decrease with decreasing the fiber length.4 In this paper we propose a three-stage amplifier for achieving a low NF and a wide dynamic range simultaneously.