International Journal of Signal Processing, Image Processing and Pattern Recognition Vol.9, No.6 (2016), pp.241-246 http://dx.doi.org/10.14257/ijsip.2016.9.6.21 ISSN: 2005-4254 IJSIP Copyright ⓒ 2016 SERSC Performance Evaluation of Hybrid amplifiers for 16 × 20 and 32 × 20 Gbps DWDM System Parveen Bagga and Himali Sarangal Student, Assistant Professor parveenbagga20@gmail.com, himali.sarangal@gmail.com Abstract In this paper, the 16 channel and 32 channel DWDM systems at 20 Gbps have been investigated for hybrid amplifiers. The performance has been analyzed on the basis of transmission distance. The comparison of BER and Q-factor for two hybrid amplifiers EDFA+RAMAN and RAMAN+EDFA at different transmission distance is done. It is observed that for 16 × 20 Gbps and 32×20Gbps DWDM system using EDFA+RAMAN provides better results than the DWDM system using RAMAN+EDFA. The analysis is done using OptiSystem 7.0 simulator. Keywords: DWDM, BER, EDFA, RAMAN, Q Factor, OptiSystem 7.0 1. Introduction DWDM technology uses multiple wavelengths to transmit information over a single fiber. Dense WDM is WDM utilizing closely spaced channels. Today the demand of network capacity increases. So to increase the information carrying capacity of the network the DWDM system is the most useful technique. In DWDM system with the increase in distance there occurs degradation of signal, so to decrease this degradation of signal hybrid amplifiers are used to boost up the signal. Basically an optical amplifier is a device which amplifies the optical signal directly without ever changing it to electricity. DWDM system uses a multiplexer at the transmitter end, which multiplexes more than one optical signal onto a single fibre and demultiplexer at the receiver to split them apart. Figure 1 is showing a basic DWDM Technology Figure 1. DWDM System For long distance communication loss of signal strength is the major problem which can be overcome by the optoelectronic repeaters in this optoelectronic repeater the signal is first converted into electric current and then regenerated with the help of transmitter but these regenerators are very complex and expensive for the DWDM systems so these days optical amplifiers are used which directly amplify the transmitter signal without any conversion of optical signal to electric signal .basically optical amplifiers amplifies the signal and reduce the attenuation. EDFA is basically used to boost up the signal by using