Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Fabry-Perot Metrology for Displacements up to 50 mm

Published

Author(s)

John R. Lawall

Abstract

A system designed to apply Fabry-Perot interferometry to the measurement of displacements is described. Two adjacent modes of a Fabry-Perot cavity are probed, and both the absolute optical frequencies and their difference are used to determine displacements via changes in cavity length. Light is coupled to the cavity via an optical fiber, making the system ideal for remote sensing applications. Continuous interrogation is not necessary, as the cavity length is encoded in the free spectral range. The absolute accuracy is determined to be below 10pm, which for the largest displacement measured corresponds to a relative accuracy of 4 x 10-10. To my knowledge this is the highest relative accuracy in a displacement measurement ever demonstrated.
Citation
Journal of the Optical Society of America B-Optical Physics

Keywords

Fabry-Perot, interferometry

Citation

Lawall, J. (2008), Fabry-Perot Metrology for Displacements up to 50 mm, Journal of the Optical Society of America B-Optical Physics (Accessed April 19, 2024)
Created October 16, 2008