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[Alb12] A two-mode interference measurement for absolute distance measurements with nanometer accuracyConférences Internationales sans actes : ICSO , ajaccio, france,Mots clés: laser ranging system interference
Résumé:
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.
Equipe:
laetitia
Collaboration:
ARTEMIS
BibTeX
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