Abstract

In long-distance transmission systems with optical in-line amplifiers, the nonlinear refractive index of the optical fibers significantly limits the transmission distance in terms of both signal-waveform distortion¹ and optical noise enhancement.^2,3 Extending the noise treatment presented in Ref. 4, we derive an analytical expression of noise evolution in cascaded in-line amplifier systems, and we evaluate the resulting signal-to-noise ratio (SNR) and allowable system length.

© 1994 Optical Society of America