Physical interpretation of inverse scattering formalism applied to self-induced transparency

The inverse scattering method (ISM) as applied to self-induced transparency (SIT) is reviewed. The linear scattering equations (Zakharov-Shabat equations) that are the basis of the inverse scattering method applied to SIT are physically interpreted. They in turn are solved by establishing an analogy with the equations are shown to follow from application of the principle of causality of the parametric amplifier analog.