A method is proposed for obtaining exact analytical solutions for the syste
m of nonlinear equations for the propagation of electromagnetic waves in di
rectional couplers with an arbitrary nonlinearity in the propagation consta
nt. The resulting solutions can be used to determine the operating characte
ristics of nonlinear directional couplers. (C) 1999 American Institute of P
hysics. [S1063-7842(99)01308-2].