When an optical wave, emitted from a monochromatic light source such as a laser, travels through a medium it is subject to a variety of effects created by the medium. Such effects are sometimes induced by the natural material characteristics which may create technical difficulties in optical transmission systems.
In telecommunications, where optical information is often transmitted via optical fibers, degradation in optical signal, such as pulse spreading or distortion, are often attributed to the dispersions created by the medium. One such dispersion is called a material dispersion which causes spreading of an optical signal pulse traveling through the medium due to the material property of the medium. When dispersed, some signal wavelengths travel faster than other wavelengths of the same signal. In addition to the material dispersion, waveguide dispersion further degrades the signal due to the signal spreading caused by the geometries and the sizes of waveguides. Furthermore, as the optical signal is spread due to the dispersion, the amplitude of the optical signal is also degraded. All these effects combined often define limitations to the efficiency of many transmission systems.