Raman Amplification in Fiber Optical Communication Systems

Edited by

  • Clifford Headley, OFS Laboratories, Somerset, NJ, U.S.A.
  • Govind Agrawal, Institute of Optics at the University of Rochester, NY, USA

Optical fiber telecommunications depend upon light traveling great distances through optical fibers. As light travels it tends to disperse and this results in some degree of signal loss. Raman amplification is a technique that is effective in any fiber to amplify the signal light as it travels through transmission fibers, compensating for inevitable signal loss.
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Practicing engineers in the telecommunications industry, especially optical fiber telecommunications. Graduate students in optical engineering and telecommunications engineering.


Book information

  • Published: December 2004
  • ISBN: 978-0-12-044506-6


...very comprehensive and covers the entire topic of Raman amplification as applied to communication systems. As befitting a book of this length, the treatment is exhaustive and provides a range of information, from historical perspective, to current implementations, to some forecasts of important technologies for the future. “Raman Amplification in Fiber Optical Communication Systems” is an excellent book to fully understand how this cutting-edge technology works...In brief, I highly recommend reading this book. - Bertrand Desthieux, Editor-in-Chief of Optical Fiber Technology

Table of Contents

Introduction: Overview of an optical telecommunication system; What is an optical fiber'Stimulated Raman scattering (SRS) in optical fibers; Benefits of SRS; The emergence of Raman amplification. Stimulated Raman Scattering in optical Fibers: Maxwell’s and the wave equation; Fiber Modes; Nonlinear Schrödinger Equation; Raman gain process; Coupled Amplitude Equations; CW coupled equations. Raman Pumping in Optical Fiber Communications: Semiconductor Lasers; Laser structure; Materials used; Current capabilities e.g. power range, wavelength range; Future trends; Raman fiber lasers; Description of the cascaded Raman fiber laser process; Description of pump sources; 9xx multimode diodes; Yb-doped cladding pumped fiber laser; Rate Equations describing the process; Performance optimization e.g. choosing fiber length, output coupler reflectivity; Multiple wavelength pumps; Higher order pump sources; Current capabilities e.g. power range, wavelength range; Comparison between the two sources. Distributed Raman amplification along the Transmission span: Optical signal-to-noise ratio; Increasing the optical signal-to-noise ratio; Increasing span reach or capacity; Equivalent noise and how to measure it; Multiple wavelength Raman pumps for gain flatness; Selecting the correct wavelength and power distribution; Co and counter pumping; Advantages of counter pumping; Reasons for co-pumping; Higher-order pumping; Why use higher order pumping? The tradeoff between going to different orders; Time division multiplexing of pumps; Tradeoff between OSNR and nonlinear penalties. Discrete Raman amplifiers: Contrast with distributed amplifiers; Rayleigh backscattered light; Noise figure now dominated by amplified spontaneous emission; Comparison of discrete Raman amplifiers with other approaches, e.g. erbium, thulium etc.; Dispersion compensating fiber (DCF); What is DCF and why is it used; Raman properties of DCF fiber which makes it attractive; Amplifier design issues; Fiber lengths; Number of stages; Optimization of fibers for dispersion compensating Raman amplifiers. Impairments and Limitations to Raman Amplification: MPI penalties; Rayleigh backscattered light; Effect on system performance; Measurement techniques; Time Domain extinction method; Electrical spectrum analyzer method; Pump signal transfer; Transient effects such as adding or dropping channels in single spans and multiple spans; FWM impairments; Pump-pump interaction; Pump-signal interaction.