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Proceedings Paper • Open Access

Absolute distance metrology for space interferometers
Author(s): B. L. Swinkels; T. J. Wendrich; N. Bhattacharya; A. A. Wielders; J. J. M. Braat

Paper Abstract

Space interferometers consisting of several free flying telescopes, such as the planned Darwin mission, require a complex metrology system to make all the components operate as a single instrument. This metrology system consists of various sub-systems to monitor distances, angles and speeds. Our research focuses on one of these sub-systems that measures the absolute distance between two satellites with high accuracy. For Darwin the required accuracy would be in the order of 10 μm over 250 meter.

To measure this absolute distance, we are currently building a frequency sweeping interferometer. It is operated by first measuring a phase in the interferometer, sweeping a tunable laser over a known frequency interval and finally measuring a second phase. By also counting the number of fringes during the sweep it is possible to determine the absolute path length difference without ambiguities. We plan on actively stabilizing the wavelength at the endpoints of the sweep on a Fabry-Perot cavity using the Pound-Drever-Hall technique. In this way the unknown distance is directly referenced to the length of the Fabry-Perot cavity.

Paper Details

Date Published: 21 November 2017
PDF: 4 pages
Proc. SPIE 10568, International Conference on Space Optics — ICSO 2004, 1056810 (21 November 2017); doi: 10.1117/12.2307964
Show Author Affiliations
B. L. Swinkels, Delft Univ. of Technology (Netherlands)
T. J. Wendrich, Delft Univ. of Technology (Netherlands)
N. Bhattacharya, Delft Univ. of Technology (Netherlands)
A. A. Wielders, TNO-TPD (Netherlands)
J. J. M. Braat, Delft Univ. of Technology (Netherlands)

Published in SPIE Proceedings Vol. 10568:
International Conference on Space Optics — ICSO 2004
Josiane Costeraste; Errico Armandillo, Editor(s)

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