title: Absolute distance measurement with micrometer accuracy using a Michelson interferometer and the iterative synthetic wavelength principle.
abstract: We present a novel system that can measure absolute distances of up to 300 mm with an uncertainty of the order of one micrometer, within a timeframe of 40 seconds. The proposed system uses a Michelson interferometer, a tunable laser, a wavelength meter and a computer for analysis. The principle of synthetic wave creation is used in a novel way in that the system employs an initial low precision estimate of the distance, obtained using a triangulation, or time-of-flight, laser system, or similar, and then iterates through a sequence of progressively smaller synthetic wavelengths until it reaches micrometer uncertainties in the determination of the distance. A further novel feature of the system is its use of Fourier transform phase analysis techniques to achieve sub-wavelength accuracy. This method has the major advantages of being relatively simple to realize, offering demonstrated high relative precisions better than 5 × 10(-5). Finally, the fact that this device does not require a continuous line-of-sight to the target as is the case with other configurations offers significant advantages.
authors.affiliation: The General Engineering Research Institute (GERI), Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, UK.
authors.forename: Khaled
authors.initials: K
authors.lastname: Alzahrani
authors.forename: David
authors.initials: D
authors.lastname: Burton
authors.forename: Francis
authors.initials: F
authors.lastname: Lilley
authors.forename: Munther
authors.initials: M
authors.lastname: Gdeisat
authors.forename: Frederic
authors.initials: F
authors.lastname: Bezombes
authors.forename: Mohammad
authors.initials: M
authors.lastname: Qudeisat
mesh_terms: D000465:Algorithms; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007368:Interferometry / Q000295:instrumentation*; D008027:Light; D011825:Radar / Q000295:instrumentation*