Talk:Material dispersion coefficient

I think the article as it stands is more than a bit misleading. In an optical fiber you cannot in general ignore the effects of the shape of the waveguide: the total dispersion is determined by the material dispersion (the dependence of index on frequency) and the waveguide dispersion (which comes from the geometry), and nor do the two effects simply add. The total dispersion is characterized by a parameter D (the pulse spreading, usually in ps/nm km). See also Dispersion (optics), although the discussion in that article is currently woefully narrow-focused to homogeneous media. —Steven G. Johnson 06:55, 4 January 2006 (UTC)[reply]

According to my knowledge, the total dispersion includes intermodal dipersion and intramodal dispersion, which in turn is divided into material dispersion and waveguide dispersion. However, normally we consider only intramodal dipsersion, so i think briefly the actical above is correct.—Preceding unsigned comment added by Terryfei (talk • contribs) 13:13, 17 July 2007