Amplified sensing of optical phase difference through the phase of the resultant field

Abstract

A generalized scheme to enhance the sensitivity in the measurement of phase difference in an optical interference by measuring the phase of the resultant field is presented. In the proposed scheme, the weak measurement in scalar optical interferometry is achieved by directly accessing the phase of the output state, rather than looking at the centroid shift in the intensity. The spatial confinement or beam-like characteristics for the optical field, an essential criterion for centroid calculation, is not a requirement for the scheme. The ability to uniquely sense and distinguish contributions to the phase difference from individual optical fields; an aspect with potential to improve the measurement accuracy in optical gyroscopes and gravitational wave sensing, is also presented.