  Using a field theory generalization of the spinning top motion, we construct
nonabelian generalizations of the sine-Gordon theory according to each
symmetric spaces. A Lagrangian formulation of these generalized sine-Gordon
theories is given in terms of a deformed gauged Wess-Zumino-Witten action which
also accounts for integrably perturbed coset conformal field theories. As for
physical applications, we show that they become precisely the effective field
theories of self-induced transparency in nonlinear optics. This provides a
dictionary between field theory and nonlinear optics.
