title: Fractional Fourier transformers through reflection.
abstract: We show that an arbitrary paraxial optical system, compounded with its reflection in an appropriately warped mirror, is a pure fractional Fourier transformer between coincident input and output planes. The geometric action of reflection on optical systems is introduced axiomatically and is developed in the paraxial regime. The correction of aberrations by warp of the mirror is briefly addressed.
authors.affiliation: Centro de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos. bwolf@fis.unam.mx
authors.forename: Kurt Bernardo
authors.initials: KB
authors.lastname: Wolf
authors.forename: Guillermo
authors.initials: G
authors.lastname: Krötzsch