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Proceedings Paper • Open Access

A two-mode interference measurement for nanometer accuracy absolute distance ranging
Author(s): Michel Lintz; Duy-Ha Phung; Alain Brillet; Christophe Alexandre

Paper Abstract

We present a laser ranging system, under development, that uses a high frequency modulated beam to achieve sub-nm resolution by the combined use of interferometric and time-of-flight measurements. We first describe how the absolute distance is extracted from a two-mode interference signal. In particular we show that the signal, which presents both optical and synthetic wavelength scales, is essential to achieve nm-scale accuracy, despite the significant long-term phase drifts in the 20 GHz detection chains. Then we present results obtained with the telemeter implemented on an optical table, for a distance of about four meters, implemented by folding the laser beam path to the target. The challenge here is to achieve a phase and amplitude measurement of two 20 GHz signals with a resolution well below 10-4 cycle and 10-4, respectively, despite the fact that the signal undergoes very strong (×3 ) amplitude changes.

Paper Details

Date Published: 20 November 2017
PDF: 11 pages
Proc. SPIE 10564, International Conference on Space Optics — ICSO 2012, 1056423 (20 November 2017); doi: 10.1117/12.2309036
Show Author Affiliations
Alain Brillet
Christophe Alexandre

Published in SPIE Proceedings Vol. 10564:
International Conference on Space Optics — ICSO 2012
Bruno Cugny; Errico Armandillo; Nikos Karafolas, Editor(s)

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