title: Propagation through apodized gratings.
abstract: It is shown that light propagation in an apodized fiber Bragg grating with a Kerr nonlinearity approximately obeys a nonlinear Schr"odinger-like equation, but with extra terms because the eigenstates of the grating vary with position. It is shown that propagation through such a grating leads to field enhancement, and to a nontrivial phase shift; an approximate expression for the reflectivity is also found.
authors.forename: M
authors.initials: M
authors.lastname: de Sterke