title: Frequency converter implementing an optical analogue of the cosmological redshift.
abstract: According to general relativity, the frequency of electromagnetic radiation is altered by the expansion of the universe. This effect-commonly referred to as the cosmological redshift--is of utmost importance for observations in cosmology. Here we show that this redshift can be reproduced on a much smaller scale using an optical analogue inside a dielectric metamaterial with time-dependent material parameters. To this aim, we apply the framework of transformation optics to the Robertson-Walker metric. We demonstrate theoretically how perfect redshifting or blueshifting of an electromagnetic wave can be achieved without the creation of sidebands with a device of finite length.
authors.affiliation: Department of Applied Physics and Photonics, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel, Belgium. vincent.ginis@vub.ac.be
authors.forename: Vincent
authors.initials: V
authors.lastname: Ginis
authors.forename: Philippe
authors.initials: P
authors.lastname: Tassin
authors.forename: Ben
authors.initials: B
authors.lastname: Craps
authors.forename: Irina
authors.initials: I
authors.lastname: Veretennicoff