Patent ID: 8477316

Claim:
An interferometer system, comprising an interferometer including an interferometer light source, radiation emitted from the light source splittable into a measuring arm and a reference arm, an object to be measured arranged in the measuring arm, the interferometer adapted to generate interferometer signals as a function of a position of the object to be measured; and a detection device adapted to detect fluctuations in a refractive index of air in at least one of (a) the measuring arm and (b) the reference arm; wherein the detection device includes a spectrometer unit, the spectrometer unit including: a spectrometer light source, bundles of rays emitted from the spectrometer light source superimposable on bundles of rays of the interferometer light source, the spectrometer light source adapted to emit radiation having a wavelength in a range of an absorption line of at least one specific air component; and at least one spectrometer detector unit adapted to generate spectrometer signals that characterize the absorption of the air component with respect to the spectrometer light-source wavelength in at least one of (a) the measuring arm and (b) the reference arm.