Optical Solitons in Fibers

It is approximately a quarter of a century since the word soliton was introduced. During this period various types of solitons were discovered in almost all areas of physics. Approximately one hundred different types of nonlinear partial differential equations were found to have soliton or soliton-like solutions mathematically. The definition of a soliton has also expanded from a narrowly defined one which refers to a localized solution of exactly integrable solution of a nonlinear partial differential equation to a more general one which refers to a relatively stable nonlinear solitary wave even if the equation is not integrable. Various definitions are used in a convenient way depending on different physical problems.