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Heterodyne interferometer with subnanometer accuracy



Darine El Haddad, Frank C. Seifert, Stephan Schlamminger, Leon S. Chao, David B. Newell, Jon R. Pratt


This paper gives a brief description of the laser interferometer system designed for the next generation watt balance experiment aimed to realize the unit of mass by direct link to Planck constant at the National Institute of Standards and Technology. The light source is an iodine-stabilized frequency-doubled Nd:YAG laser at λ=532nm. Three heterodyne interferometers with subnanometer non-linearity errors measure the angular and the vertical displacements of the induction coil.
Proceedings Title
CPEM 2014 Digest
Conference Dates
August 24-29, 2014
Conference Location
Rio de Janeiro
Conference Title
Conference on Precision Electromagnetic Measurements


heterodyne interferometry, non-linearity errors, watt balance, Planck constant, unit of mass


El, D. , Seifert, F. , Schlamminger, S. , Chao, L. , Newell, D. and Pratt, J. (2014), Heterodyne interferometer with subnanometer accuracy, CPEM 2014 Digest, Rio de Janeiro, -1, [online], (Accessed April 12, 2024)
Created August 24, 2014, Updated November 29, 2019