Enhancement of angular displacement measurement sensitivity by modified-SU(2) interferometry

Abstract

In this paper, we analysis the angular displacement measurements using the homodyne detection scheme in a modified-SU(2) Mach-Zehnder interferometer (MZI). Three parametric amplifiers (PAs) are used in order to increase the number of photons and to reduce the shot-noise. We also consider quantum Fisher information (QFI) and derive expressions for single- and two-parameter cases and corresponding quantum Cramér-Rao bounds (QCRB). We find that angular displacement sensitivity exceeds the standard quantum limit (SQL) or shot-noise limit (SNL) and approaches single- and two-parameter QCRB. Finally, we look at the impact of photon losses on the sensitivity of interferometer. © 2023 SPIE.