Information Theory Applied to Fiber-Optic Transmission: Limits to Spectral Efficiency of Optical Fib

Speaker: Dr. René-Jean Essiambre
Bell Labs, Alcatel-LucentAbstract: Fiber-optic communication systems constitute the backbone of the communication network infrastructure. The main physical elements of the optical paths in these networks are the optical fiber (as the physical medium for transport) and the optical amplifier (to combat signal attenuation). The transmission bandwidth available over each optical path is enormous, on the order of 10 THz. Despite such a large bandwidth being available, there is a tremendous demand to increase the capacity of fiber-optic communication systems by increasing spectral efficiencies to multiple bits/s/Hz while still maintaining transmission distances on the order of a few thousands of kilometers. Achieving such high spectral efficiency requires using signals with multiple levels in phase and/or amplitude, and possibly using both states of polarization. Transmission of such multilevel signals becomes increasingly impacted by the Kerr fiber nonlinearity, a physical phenomenon unique to the 'fiber channel'. The Kerr nonlinearity results in signal distortions that rapidly increase with signal power. The question then arises: how to apply Shannon's information theory to the `fiber channel' and is there a maximum spectral efficiency associated to the Kerr fiber nonlinearity?In this talk, we will describe how we applied Shannon's theory to the `fiber channel' and present the early results in the direction of conservatively estimating the fiber capacity. A spectral efficiency of ~7 bits/s/Hz (in a single polarization) for transmission over 1000 km in an optically-routed network will be shown to be achievable.Biography: René-Jean Essiambre is a Distinguished Member of Technical Staff at Bell Labs, Alcatel-Lucent. He received his doctorate from Université Laval and studied at the University of Rochester before joining Lucent Technologies (now Alcatel-Lucent) in 1997. Dr. Essiambre is contributing to the design of advanced optical transmission systems, especially in relation to the management of fiber nonlinearities. Interests include modulation formats, detection and optimization techniques for the design of optically routed networks to increase capacity, optical transparency and functionality of wavelength-division multiplexed communication systems. He is a recipient of the 2005 Engineering Excellence Award from OSA, where he is a Fellow.Host: Gerhard Kramer, gkramer@usc.edu, EEB 536, x07229

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Gerrielyn Ramos