Material dispersion coefficient 49829 197672771 2008-03-12T07:50:41Z SmackBot 433328 Date the maintenance tags or general fixes {{Disputed|date=March 2008}} In an [[optical fiber]], the '''material dispersion coefficient''', ''M''(λ), characterizes the amount of [[pulse broadening]] by material [[dispersion (optics)|dispersion]] per unit length of fiber and per unit of [[spectral width]]. It is usually expressed in [[picosecond]]s per ([[nanometre]]·[[kilometre]]). For many optical fiber materials, ''M''(λ) approaches zero at a specific [[wavelength]] λ<sub>0</sub> between 1.3 and 1.5 [[μm]]. At wavelengths shorter than λ<sub>0</sub>, ''M''(λ) is negative and increases with wavelength; at wavelengths longer than λ<sub>0</sub>, ''M''(λ) is positive and decreases with wavelength. Pulse broadening caused by material dispersion in a unit length of optical fiber is given by the product of ''M''(λ) and [[spectral width]] (Δλ). ==References== *[[Federal Standard 1037C]] <!--Categories--> [[Category:Fiber optics]] {{optics-stub}}