Optimal phase sensitivity of an unbalanced Mach-Zehnder interferometer

Abstract

In this paper we address the problem of optimizing an unbalanced Mach-Zehnder interferometer, for a given pure input state and considering a specific detection scheme. While the optimum transmission coefficient of the first beam splitter can be uniquely determined via the quantum Fisher information only [Phys. Rev. A 105, 012604 (2022)], the second beam splitter transmission coefficient is detection-scheme dependent, too. We systematically give analytic solutions for the optimum transmission coefficient of the second beam splitter for three types of widely used detection schemes. We provide detailed examples including both Gaussian and non-Gaussian input states, showing when an unbalanced Mach-Zehnder interferometer can outperform its balanced counterpart in terms of phase sensitivity.

22 pages, 14 figures

References in corpus (10)

• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Mach-Zehnder Interferometry at the Heisenberg Limit with coherent and squeezed-vacuum light
• Fundamental precision limit of a Mach-Zehnder interferometric sensor when one of the inputs is the vacuum
• Phase sensitivity bounds for two-mode interferometers
• Single- versus two-parameter Fisher information in quantum interferometry
• Optimal Mach-Zehnder phase sensitivity with Gaussian states
• Quantum Fisher information maximization in an unbalanced interferometer
• Phase sensitivity for an unbalanced interferometer without input phase-matching restrictions
• Quantum enhancement of sensitivity achieved by photon-number-resolving detection in the dark port of a two-path interferometer operating at high intensities
• Field operator transformations in Quantum Optics using a novel graphical method with applications to beam splitters and interferometers