Description of a wave packet propagating in anomalous dispersion media-a new expression of propagation velocity

Masayoshi Tanaka

    Research output: Contribution to journalArticle

    13 Citations (Scopus)


    The propagation velocity of a wave packet applicable to anomalous dispersion media is newly derived using the saddle point method. This velocity includes the effects of both packet deformation and spreading, and coincides with the group velocity at the normal dispersion limit. A method to determine the saddle point frequency from a given initial condition is presented and the trajectory of a wave packet incident on a semi-infinite medium is obtained by integrating the new propagation velocity. It reveals that the propagation of a wave packet in anomalous dispersion media is characterized by three regions, i.e. backward, fast and slow propagation regions. The difficulty of group velocity in anomalous dispersion media is overcome.

    Original languageEnglish
    Article number004
    Pages (from-to)1049-1067
    Number of pages19
    JournalPlasma Physics and Controlled Fusion
    Issue number7
    Publication statusPublished - Dec 1 1989


    All Science Journal Classification (ASJC) codes

    • Nuclear Energy and Engineering
    • Condensed Matter Physics

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