Nonlinear Effects in Optical Fibers

Abstract

Abstract Advanced lightwave communications systems relying on optical amplification and wavelength‐division multiplexing can carry dozens of wavelengths over thousands of kilometers of optical fibers between optoelectronic regeneration points. Large optical powers confined to the small core of optical fibers over enormous distances exacerbate the effects of optical nonlinearities that can degrade signal quality. Optical nonlinearities in optical fibers include stimulated Raman scattering, stimulated Brillouin scattering, self‐phase modulation, cross‐phase modulation, and four‐photon mixing. These nonlinearities can degrade lightwave communication systems in many different ways including distortion of pulse shapes, spectral broadening, generation of new unwanted frequencies, optical crosstalk, and signal depletion. Various techniques have been developed to mitigate the effects of optical nonlinearities in fibers.