material dispersion: In optical fiber communication, the wavelength dependence of the velocity of propagation (of the optical signal) on the bulk material of which the fiber is made. Note 1: Because every optical signal has a finite spectral width, material dispersion results in spreading of the signal. Note 2: Use of the redundant term "chromatic dispersion" is discouraged. Note 3: In pure silica, the basic material from which the most common telecommunication-grade fibers are made, material dispersion is minimum at wavelengths in the vicinity of 1.27 m (slightly longer in practical fibers).
profile dispersion: In an optical fiber, that dispersion attributable to the variation of refractive index contrast with wavelength. Profile dispersion is a function of the profile dispersion parameter.
waveguide dispersion: Dispersion, of importance only in single-mode fibers, caused by the dependence of the phase and group velocities on core radius, numerical aperture, and wavelength. (188) Note 1: For circular waveguides, the dependence is on the ratio, a /, where a is the core radius and is the wavelength. Note 2: Practical single-mode fibers are designed so that material dispersion and waveguide dispersion cancel one another at the wavelength of interest.