title: Squared-field amplitude modulus and radiation intensity nonequivalence within nonlinear slabs.
abstract: This paper presents an approach to wave propagation inside the Fabry-Pérot framework. It states that the time-averaged Poynting vector modulus can be nonequivalent to the squared-field amplitude modulus. This fact permits the introduction of a kind of nonlinear medium whose nonlinearity is proportional to the time-averaged Poynting vector modulus. Its transmittance is calculated and found to differ from that obtained for a Kerr medium, whose nonlinearity is proportional to the squared-field amplitude modulus. The latter emphasizes the nonequivalence of these magnitudes. A space-time symmetry analysis shows that the Poynting nonlinearity should be possible only in noncentrosymmetric materials.
authors.affiliation: Departamento de Física, Centro de Ciências Exatas e da Natureza, Universidade Federal da Paraíba, Caixa Postal 5008 CEP 58051-970, João Pessoa, Paraíba, Brazil. agl@fisica.ufpb.br
authors.forename: Alberto
authors.initials: A
authors.lastname: Lencina
authors.forename: Pablo
authors.initials: P
authors.lastname: Vaveliuk