We give a quantitative meaning to the often-used expression: in spatial solitons, diffraction is balanced by nonlinear refractive-index effects. After pointing out how the electric field shape and its derivatives relate to the magnetic field, we show that the balance of magnetic and electric stored energies describes what happens in a variety of linear and nonlinear waves, including linear guided waves, nonlinear self-guided waves in quadratic and cubic media, and in cases where several frequencies are present and energy exchange may occur. We give exact, electromagnetic theory results and also explain how the energy balance works in the slowly varying approximation.
© 2001 Optical Society of America
Nadeem Ansari and Colin Pask, "Energy balance in linear and nonlinear waves," J. Opt. Soc. Am. B 18, 36-44 (2001)