1997/09/30 by Yuji Kodama, Kodama, Yuji · 1 citation
Engineering · Physics and Astronomy · #Exactly Solvable and Integrable Systems (nlin.SI) #FOS: Physical sciences #Nonlinear Photonic Systems #Nonlinear Waves and Solitons #Optical Network Technologies
paper · pdf · doi:10.48550/arxiv.solv-int/9709012
openalex publication_date 1997/09/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present a model of optical communication system for high-bit-rate data transmission in the nonreturn-to-zero (NRZ) format over transoceanic distance. The system operates in a small group velocity dispersion regime, and the model equation is given by the Whitham equations describing the slow modulation of multi-phase wavetrains of the (defocusing) nonlinear Schrödinger (NLS) equation. The model equation is of hyperbolic type, and certain initial NRZ pulse with phase modulation develops a shock. We then show how one can obtain a global solution by choosing an appropriate Riemann surface on which the Whitham equation is defined. The present analysis may be interpreted as an alternative to the method of inverse scattering transformation for the NLS solitons. We also discuss wavelength-division-multiplexing (WDM) in the NRZ format by using the Whitham equation for a coupled NLS equation, and show that there exists a hydro-dynamic-type instability between channels.