Performance Evolution of Hybrid Optical Amplifiers for WDM Systems

Abstract

For several years now, optical fiber communication systems are being extensively used all over the world for telecommunication, video and data transmission purposes. The demand for transmission over the global telecommunication network will continue to grow at an exponential rate and only fiber optics will be able to meet the challenge. Presently, almost all the trunk lines of existing networks are using optical fiber. This is because the optical fiber capable of allowing the transmission of many signals over long distances. However, attenuation is the major limitation imposed by the transmission medium for long-distance high-speed optical systems and networks. So with the growing transmission rates and demands in the field of optical communication, the electronic regeneration has become more and more expensive. The powerful optical amplifiers came into existence, which eliminated the costly conversions from optical to electrical signal and vice versa. Due to the need of longer and longer unrepeated transmission distances Wavelength division multiplexing optical transport networks are expected to provide the capacity required to satisfy the growing volume of telecommunications traffic in a cost-effective way. This thesis is investigates the potential of optical amplifier operating at 16×10 Gb/s in optical communication system. In this thesis, the 16 channel WDM systems at 10 Gbps have been investigated for the various optical amplifiers and hybrid amplifiers and the performance has been compared on the basis of transmission distance, dispersion and pumping. The amplifiers EDFA and SOA have been investigated independently and further compared with hybrid amplifiers like RAMAN-EDFA and RAMAN-SOA. It is observed that optical hybrid amplifier RAMAN-EDFA provides the highest output power (12.017dBm) and least bit error rate (1×10-40) at 100 km for dispersion 2ps/nm/km and 4ps/nm/km as compare to other optical amplifier. Four types of pumping have been investigated independently and compared. It is observed that pump 2 of RAMAN-EDFA provides the highest output power (12.048 dBm and 12 dBm ) and least bit error rate (5.44×10-26 and 1.91×10-12) at 140 km for dispersion 2ps/nm/km and 4ps/nm/km respectively as compare to other pumping amplifier. It is also observed that fiber length for pumping of the RAMAN-EDFA is acceptable only upto 30 kms (at this length power is 12.076dBm). After 30 Kms, the power is decreased instantly.