Fabry-Perot Metrology for Displacements up to 50 mm
John R. Lawall
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.
Journal of the Optical Society of America B-Optical Physics
Fabry-Perot Metrology for Displacements up to 50 mm, Journal of the Optical Society of America B-Optical Physics
(Accessed February 26, 2024)