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Theoretical description, optimisation and implementation of multi-wavelength interferometric methods for absolute distance metrology

Optical interferometry has been applied for distance metrology since the time of Michelson and Benoit. One of the current challenges in interferometric metrology is to achieve long range unambiguous measurement, for example of gauge blocks up to 500 mm in length and in interferometric telescopes, where path length differences can be 10's of meters. A theoretical analysis of multi-wavelength interferometry describing the relationship between unambiguous measurement range, reliability and the measurement wavelengths is the main focus of this research. The results of this analysis allow the derivation of a theoretical model that can be used to develop wavelength selection strategies. Hence, it is possible to maximize the reliability in the calculated fringe order for a given measurement range, number of wavelengths, and level of phase noise. Optimum wavelength selection strategies have been implemented in a fibre optic four-wavelength interferometer and experiments have been carried out showing an overall dynamic range of 1 part in 2x10 6, or a resolution of 8 nm in >18 mm.

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:713492
Date January 2010
CreatorsFalaggis, Konstantinos
PublisherUniversity of Leeds
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation

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