Output Signal Power Analysis in Erbium-Doped Fiber Amplifier with Pump Power and Length Variation Using Various Pumping Techniques

The scope of this paper is to analyze the output signal power with pump power and length variation in cascaded EDFA simulation model performance. This paper describes the simulation model of Erbium-Doped Fiber Amplifier (EDFA) of variable lengths (10？m, 50？m, and 120？m) with dual pumping techniques (dual forward pumping with two 980？nm wavelengths, dual forward and backward pumping with two 980？nm wavelengths) and Tri-pumping techniques. The simulation models consist of input source and pump power coupled by WDM coupler which gives optimized signal power in the above-mentioned simulation model. The simulation model consists of source with multiple wavelengths (1520？nm–1618？nm), pumping source with the wavelength 980？nm, isolator, and filter. The resulting models accurately represent EDFA optimized output signal power. Simulation results show that choosing careful fiber length 120？m and pump power 1？W in dual pumping provided 0.07？W optimized output signal power compared to other pumping techniques. 1. Introduction As the demand of high data speed networks is increasing, an answer to long distance communication system is optical communication systems which employ optical fiber that can be used as a medium for telecommunication and networking. The light propagates through the optical fiber with little attenuation compared to electrical cables. An optical amplifier is a device that amplifies an optical signal directly without the need to first convert it to an electrical signal in optical fiber communications. EDFAs are mostly used as preamplifiers with multichannel amplification without crosstalk and also multigigabit transmission rates by low bit errors [1]. Most important element of EDFA technology is the Erbium-Doped Fiber (EDF), which is a conventional silica fiber doped with Erbium. Erbium-doped fiber amplifiers have attracted the most attention because they operate in the wavelength region near 1.55？μm. The deployment of EDFA in WDM systems has revolutionized the field of optical fiber communications and led to light wave systems with capacities exceeding 1？Tb/s. 1.1. Basic Principle of EDFA Amplification in an Erbium-doped fiber amplifier occurs through the mechanism of stimulated emission. When the Erbium is illuminated with light energy at a suitable wavelength (either 980？nm or 1480？nm), it is excited to a long lifetime intermediate state level 2 following which it decays back to the ground state by emitting light within the 1500–1600？nm bands [2]. If light energy already exists within the 1500–1600？nm band, for example, due to a signal channel