Super-sensitive angular displacement estimation via an SU(1,1)-SU(2) hybrid interferometer

Abstract

In this paper, we propose a protocol for angular displacement estimation based upon orbital angular momentum coherent state and a SU(1,1)-SU(2) hybrid interferometer. This interferometer consists of an optical parametric amplifier, a beam splitter and reflection mirrors, hereon we use a quantum detection strategy −− balanced homodyne detection. The results indicate that superresolution and super-sensitivity can be realized with ideal condition. Additionally, we study the impact of photon loss on the resolution and the sensitivity, and the robustness of our protocol is also discussed. Finally, we demonstrate the advantage of our protocol over SU(1,1) and summarize the merits of orbital angular momentum-enhanced protocol.

Effects of losses on the sensitivity of an actively correlated Mach-Zehnder interferometer

“…Such a "rule-out" protocol was introduced by Jarzyna [35], where the issue is resolved by introducing the phaseaveraging of the three-mode input state via a common phase shift. The QFI obtained by the phase-averaging method can give the proper phase-sensing limit without any external phase reference [36,37].…”

“…where |n is the photon number state. The reference framed between the inputs and the measurement is removed by phase averaging the input state as [36,37]…”

Nonlinear interferometry in all spatiotemporal degrees of freedom

“…Subsequently, other types of states have been considered for the seed [5]. The nonlinear SU(1,1) interferometer has been used in different applications [6,7].…”

Optimal phase sensitivity by quantum squeezing based on a Mach–Zehnder interferometer

“…1: the input (classical state and quantum state); 2: the interferometer scheme. For example, a MZI is made up of a beam splitter (BS); an SU(1,1) interferometer [8,9] contains an optical parametric amplification or a four wave mixing (FWM) process [10][11][12] and a hybrid interferometer consists of a BS and a FWM; 3: detection method [13]. The useful detection may contain intensity sum or difference detection [14], homodyne detection [15,16], parity measurement [17].…”