Quantum optical metrology in the lossy $SU(2)$ and $SU(1,1)$ interferometers

Abstract

We study the phase sensitivity in the conventional $SU(2)$ and nonconventional $SU(1,1)$ interferometers with the coherent and squeezed vacuum input state via the quantum Cramer-Rao bound. We explicitly construct the detection scheme that gives the optimal phase sensitivity. For practical purposes, we show that in the presence of photon loss, both interferometers with proper homodyne detections, are nearly optimal. We also find that unlike the coherent state and squeezed vacuum state, the effects of the imperfect detector on the phase sensitivity cannot be asymptotically removed for a generic coherent-squeezed state by increasing the amplifier gain of the OPA.

6 pages, 8 figures, the errors due to the incorrected expression of a matrix are corrected, more references are added

References in corpus (3)

• Quantum Optical Metrology -- The Lowdown on High-N00N States
• Mach-Zehnder Interferometry at the Heisenberg Limit with coherent and squeezed-vacuum light
• Bounds on Quantum Multiple-Parameter Estimation with Gaussian State

Cited by in corpus (3)

• Entanglement-enhanced quantum metrology: from standard quantum limit to Heisenberg limit
• Practical resources and measurements for lossy optical quantum metrology
• SU(1,1) interferometry with parity measurement