Eur. Phys. J. D (2021) 75: 256
https://doi.org/10.1140/epjd/s10053-021-00259-5

Regular Article - Quantum Optics

The design of a new fiber optic sensor for measuring linear velocity with picometer/second sensitivity based on weak-value amplification

¹ Institute of Geophysics and Geomatics, China University of Geosciences, 430074, Wuhan, China
² School of Automation, China University of Geosciences, 430074, Wuhan, China
³ Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex Systems, 430074, Wuhan, China
⁴ Engineering Research Center of Intelligent Technology for Geo-Exploration, Ministry of Education, Wuhan, China

^d xyhu@cug.edu.cn

Received: 29 June 2021
Accepted: 1 September 2021
Published online: 24 September 2021

Abstract

We put forward a new fiber optic sensor for measuring linear velocity with picometer/second sensitivity with weak-value amplification based on generalized Sagnac effect [Phys. Rev. Lett.93, 143901(2004)]. The generalized Sagnac effect was first introduced by Yao et al., which included the Sagnac effect of rotation as a special case and suggested a new fiber optic sensor for measuring linear motion with nanoscale sensitivity. By using a different scheme to perform the Sagnac interferometer with the probe in momentum space, we have demonstrated the new weak measure protocol to detect the linear velocity by amplifying the phase shift of the generalized Sagnac effect. Given the maximum incident intensity of the initial spectrum, the detection limit of the intensity of the spectrometer, we can theoretically give the appropriate pre-selection, post-selection and other optical structures before the experiment. Our numerical results show our scheme with weak-value amplification is effective and feasible to detect linear velocity with picometer/second sensitivity which is three orders of magnitude smaller than the result $\nu$=4.8 $\times$${10}^{-9}$ m/s obtained by generalized Sagnac effect with same fiber length.