INTERFEROMETRY WITH AN ACHROMATIC INTERFEROMETRIC SUPERPOSITION OF ELECTROMAGNETIC FIELDS

摘要

An interferometer apparatus for an achromatic interferometric superposition of electromagnetic fields, with a dual beam path interferometer, comprises a beam splitter being arranged for splitting an input beam into a first beam propagating along a first interferometer arm (A1) including at least one deflection mirror and a second beam propagating along a second interferometer arm (A2) including at least one deflection mirror, wherein the first and second interferometer arms have an identical optical path length, and a beam combiner being arranged for recombining the first and second beams into a constructive output and a destructive output, wherein reflective surfaces of the beam splitter and the beam combiner are arranged such that, in the first interferometer arm compared with the second interferometer arm, one additional Fresnel reflection at an optically dense medium is provided and a propagation of the electromagnetic fields of the first and second beams, when recombined by the beam combiner, results in a wavelength-independent phase difference of π between the contributions of the two interferometer arms to the destructive output, and the first interferometer arm includes a balancing transmission element being arranged for balancing a chromatic dispersion and Fresnel losses in the first and second interferometer arms. Furthermore, an interferometric measurement apparatus and an interferometric measurement method are described.