title: Geometric phase in a flat space for electromagnetic scalar waves.
abstract: We show the existence of a fundamental geometric phase for classical electromagnetic fields arising after cyclic paths in a plane instead of a sphere. This phase is dispersive, is not related to polarization, distinguishes geometrical from wave optics, and can be easily measured in an interferometric arrangement.
authors.affiliation: Departamento de Optica, Faculdad de Ciencias Físicas, Universidad Complutense, 28040 Madrid, Spain. alluis@fis.ucm.es
authors.forename: Alfredo
authors.initials: A
authors.lastname: Luis