Paper Title
Different Transmission Schemes and Optimal Fiber Lengths for a High Performance Flatband Hybrid Amplifier based All Optical Communication System

Abstract
Fiber optic systems are important telecommunication infrastructure for world- wide broadband networks. Wide bandwidth signal transmission with low delay is a key requirement in present day applications. Optical fibers provide enormous and unsurpassed transmission bandwidth with negligible latency, and are now the transmission medium of choice for long distance and high data rate transmission in telecommunication networks. One of the primary limitations in optical communication is attenuation, which will affect the transmission distance of the optical signal. This is overcome by using all-optical amplifiers. A novel approach of designing a hybrid amplifier with a combination of a single mode (SM) erbium ytterbium co-doped fibre amplifier (EYDFA) and a discrete Raman amplifier (RA) is analyzed to flatten its gain over the optical spectrum of the C and L bands. The amplifier with 40 Gb signals as the input and with different transmission methods are simulated using Optisystem simulation software. Different combinations of input is simulated and analysed for BER, OSNR, and Eye diagrams. The simulation is performed with five optimized pumping signals spaced semi-unequally are applied in forward, backward and both forward and backward directions. The performance of the amplifier in forward, backward, and both forward and backward schemes are analysed for maximum gain, noise figure and OSNR. This communication system finds use in cable television or community antenna television (CATV) and telecommunication networks, satisfy the increased number of user demands in the local area network (LAN) and offer uniform amplification to the cable TV or fiber to the home DWDM optical communication signals over the L and C bands. Keywords - Single Mode (SM), Erbium ytterbium Co-doped Fibre Amplifier (EYDFA), Community Antenna Television (CATV).