Second Order Dispersion
The dispersion resulting from wavelength dependence in the propagation of light, which tends to spread out or delay the light depending on color, hence it is often known as group delay dispersion, Dλ. Typical units are [ps2]. The group velocity delay (GVD), typical units are [ps2/km], is group delay dispersion as a function of length.
Related Terms: Chromatic Dispersion, Group Delay Dispersion (GDD), Group Velocity Delay (GVD)