Amplification of spatial solitons in quadratic nonlinear media under conditions for second-harmonic generation is
addressed. Under the action of gain at a given frequency band the energy has to be redistributed among the multiple-frequency
waves that form the solitons, which ought to reshape accordingly. It is shown that solitons in quadratic nonlinear media
appear to be well suited for such purpose. Practical implementation conditions are discussed.
Torner, L. Amplification of quadratic solitons. "Optics communications", Agost 1998, vol. 154, núm. 1, p. 59-64.