www.tjprc.org editor@tjprc.org INFLUENCE OF ASE ON THE PERFORMANCE OF EDFA & YDFL IN FIBER AMPLIFIERS MONALISA ROUT, MINU SAMANTARAY, RINA MAHAKUD & MILLEE PANIGRAHI Department of Electronics and Telecommunication Engineering, Trident Academy of Technology, Bhubaneswar, Odisha, India ABSTRACT Fiber amplifiers are replacing conventional bulk optical devices in a variety of applications. Ytterbium-doped fibers are of particular interest in high power applications due to their numerous advantages arising from a simple electronic structure. The behavior of Ytterbium-doped fiber devices is however strongly influenced by the selection of absorption and emission wavelengths and other parameters. By careful theoretical analysis the performance of the fiber device can be optimized and to estimate the influence of amplified spontaneous emission, photo darkening and other such phenomena. In the work, effect of ASE for EDFA and YDFL are investigated. Due to the effect of ASE the gain of fiber amplifier is reduced. The effect of ASE is more in EDFA than in YDFL. In the simulation result it is found that gain is less in case of EDFA than YDFL. So YDFL is preferred due to high peak power, large pulse energy and low ASE. The specific properties and characteristics of Ytterbium-doped fibers which make them highly attractive for high power fiber applications. KEYWORDS: Erbium Doped Fiber Amplifier, Ytterbium Doped Fiber Amplifier, ASE INTRODUCTION Erbium doped fiber amplifiers can be used for amplifying high speed digital signal which has low insertion loss, ease of achieving travelling wave amplification and immunity to crosstalk in wavelength division multiplexed systems. The noise figure is very low for a Erbium doped fiber amplifier. In case of Yb-doped fiber considered ring and linear cavity Yb-dopped fiber. In case of YDFA, the Q-switched laser pulses are very useful in applications of industrial manufacturing, laser ranging because of their unique characteristics in high peak power, large pulse energy and obtaining narrow line width. So YDFL is better than other fiber lasers. But in case of EDFA three types of noise is generated at the receiver (i) signal to spontaneous (ii) spontaneous to spontaneous and circuit noise. Noise and Nonlinear Effects Noise is any deviation from the original output signal which is associated with random processes. An amplifier amplifies the input seed along with produces excess unwanted noise. In an optical amplifier, the noise usually occurs in the form of spontaneous emission. By the quantum effects in the gain medium, spontaneous emission is created and is typically non-directional. However, in a fiber-based gain medium, amplified spontaneous emission (ASE) is seen due to the large aspect ratio and wave guidance which can cause a highly directional amplification. ASE is the most significant noise in optical amplifiers that limits the gain of the device. The long interaction lengths in fibers combined with the light confinement in a relatively small core area results in high optical intensities inside the core which leads to various International Journal of Electrical and Electronics Engineering Research (IJEEER) ISSN(P): 2250-155X; ISSN(E): 2278-943X Vol. 5, Issue 1, Feb 2015, 119-126 © TJPRC Pvt. Ltd.