Precision displacement interferometry with stabilization of wavelength on air

0386128 - ÚPT 2013 RIV CZ eng C - Conference Paper (international conference)
Lazar, Josef - Holá, Miroslava - Hrabina, Jan - Buchta, Zdeněk - Číp, Ondřej
Precision displacement interferometry with stabilization of wavelength on air.
Optics and Measurement 2012. Proceedings of the International Conference. Praha: Institute of Plasma Physics, 2012 - (Vít, T.; Kovačičinová, J.; Lédl, V.), s. 81-85. ISBN 978-80-87026-02-1.
[Optics and Measurement 2012. Liberec (CZ), 16.10.2012-18.10.2012]
R&D Projects: GA ČR GA102/09/1276; GA TA ČR TA02010711; GA TA ČR TE01020233; GA MŠMT ED0017/01/01; GA ČR GPP102/11/P820
Institutional support: RVO:68081731
Keywords : Refractometry * nanopositioning * interferometry * nanometrology
Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

We present an interferometric technique based on differential interferometry setup for measurement in the subnanometer scale in atmospheric conditions. The motivation for development of this ultraprecise technique is coming from the field of nanometrology. The key limiting factor in any optical measurement are fluctuations of the refractive index of air representing a source of uncertainty on the 10'6 level when evaluated indirectly from the physical parameters of the atmosphere. Our proposal is based on the concept of overdetermined interferometric setup where a reference length is derived from a mechanical frame made from a material with very low thermal coefficient on the 1 O'8 level. The technique allows to track the variations of the refractive index of air on-line directly in the line of the measuring beam and to compensate for the fluctuations. The optical setup consists of three interferometers sharing the same beam path where two measure differentially the displacement while the third represents a reference for stabilization of the wavelength of the laser source. The principle is demonstrated on an experimental setup and a set of measurements describing the performance is presented.
Permanent Link: http://hdl.handle.net/11104/0215508