title: Importance of self-phase modulation for amplitude- and phase-modulated coherent optical transmission systems: a comparison.
abstract: We demonstrate that the amount of self-phase modulation in a coherent optical transmission system grows more slowly for a phase-modulated than for an amplitude-modulated signal. Signal degradation is discussed in terms of variations in the spectral contents of the amplitude and phase modulations, and explicit analytical expressions are given for the linear modulation indices of phase and amplitude of phase-shift keying coherent transmission systems.
authors.affiliation: Institute for Electromagnetic Field Theory, Chalmers University of Technology, S-412 96 Gbteborg, Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Anderson
authors.forename: M
authors.initials: M
authors.lastname: Lisak
authors.forename: T
authors.initials: T
authors.lastname: Reichel