ECSE Departmental Research Seminar, Wednesday 25th May 2005

Speaker: Andrew Chan, Research Student, ECSE, Monash University

Abstract:

It has been forty years since ARPANet was first introduced in 1960’s. This is the age of information. Individuals, businesses, militaries and academics are keen to access information and communicate widely and quickly. These enthusiasms have motivated advances in technologies, especially development in long-haul communication system at an incredible rate. Moreover, people’s needs are ever-changing. Ordinary plain text information and telephone voice conversation are not enough to satisfy people’s needs. What they want is graphical representation and animation of information and video conferencing. These lead to a dramatic increase in data size and communication traffic. In order to carry all the huge data traffic, an optical network must be used. Nowadays, over 80 percent of the world’s long-distance data and voice traffic is carried over optical communication systems.

An amplifier-based, all-optical communication network is foreseeable in the next generation of high-capacity long-reach communication networks. DWDM technology and optical amplifiers are definitely the infrastructure of the future networks. This is because DWDM can increase the number of channels over the signal bandwidth and optical amplifiers can overcome the fiber propagation power loss and improve the detection performances, thus, increase the repeater spacing.

It has been prove that hybrid fiber amplifiers (HFA) can increase the gain-bandwidth, transmission capacity, span length, OSNR and reduce nonlinear effects in a transmission system. However, there is no answer to which HFA configurations work best. Since the design of a HFA is a complex problem with a wide degree of freedom and it is difficult to optimize a HFA in all aspects.

In this research, hybrid fiber Raman-EDF amplifiers have been studied comprehensively in the past twenty months. Theoretical, analytical and numerical models capable of predicting the transient behavior, ASE noise, double Rayleigh backscattering (DRB) noise, nonlinear impairment and OSNR have been studied in detail. The influences of different configurations of the HFA on the transient responses, amplifier noises and nonlinear impairments have been investigated. Based on all the results obtained, in the next fifteen months, a novel hybrid fiber Raman-EDF amplifier will be suggested and it will also be optimized in the OSNR domain while the gain-bandwidth and transmission capacity will be kept at practical level.

About the speaker:

Mr. Andrew Che On Chan, Postgraduate Research Student, Centre for Telecommunications and Information Engineering Monash University, Australia, Supervisors: Dr. Malin Premaratne, Candidate for the degree of Doctor of Philosophy of Engineering Science, Previous Degrees: Bachelor of Engineering in Electronic and Information Engineering from the Hong Kong Polytechnic University (HKPU), Current Research Interests: Optical fiber communications, modeling Raman fiber amplifiers and erbium-doped fiber amplifiers.