Joint International Advanced Engineering and Technology Research Conference (JIAET)

The Theoretical Limit of Sagnac Effect

Xiaohua Tian, Kun Chen

Published Jan 1, 2018• 1 citation

Abstract

The precision of optical gyroscope can be improved by enhancing Sagnac effect.Aiming at the accuracy of optical gyroscope restricted by the theoretical limit, shot noise limit, we firstly analyze the theoretical limit of Sagnac effect in optical regime with quantum theory, and point out the physical reasons for the precision limit.And then a quantum entanglement state, Yurke state, with photon number difference measurement is advised to break through shot noise limit for Sagnac effect enhancement.This proposed scheme can achieve the true quantum limit, Heisenberg limit, and offer a new idea for improving the performance of optical sensors based on Sagnac effect.

DOI: 10.2991/jiaet-18.2018.77

Related papers

A scheme for Sagnac-effect quantum enhancement with Fock state light input

Kun Chen, Shuxin Chen, De-Wei Wu +2 more

Sagnac effect enhancement can improve optical gyro precision. For a certain input intensity, we suggest that the other input port of beam splitter (BS) should be fed with some quantum light to break through shot noise limit (SNL) to improve Sagnac effect without increasing radiation-pressure noise (NRP). We design a Sagnac effect quantum enhancement criterion (SQEC) to judge whether some quantum light can enhance Sagnac effect and present a Sagnac effect enhancement scheme that utilizing Fock state light and parity measurement technique to extract the output phase. The results of the theoretical analysis show that the maximum sensitivity can be reached at θ = 0, and the phase precision can break through SNL and even achieve Heisenberg limit (HL). When the Fock state average photon number n is far less than coherent state, the minimum measurable angular rate is improved with 2 n + 1 times, which can deduce shot noise and increase NRP little.

Chinese Physics BAug 1, 20172 citations

Entanglement-enhanced optical gyroscope

Matthias Fink, Fabian Steinlechner, Johannes Handsteiner +3 more

Abstract Fiber optic gyroscopes (FOG) based on the Sagnac effect are a valuable tool in sensing and navigation and enable accurate measurements in applications ranging from spacecraft and aircraft to self-driving vehicles such as autonomous cars. As with any classical optical sensors, the ultimate performance of these devices is bounded by the shot-noise limit (SNL). Quantum-enhanced interferometry allows us to overcome this limit using non-classical states of light. Here, we report on an entangled-photon gyroscope that uses path-entangled NOON-states (N = 2) to provide super-resolution and phase sensitivity beyond the shot-noise limit.

arXiv:1810.02213New Journal of PhysicsApr 23, 201974 citations

Quantum-enhanced atomic gyroscope with tunable precision

J. P. Cooling, Jacob Dunningham

Abstract We model a gyroscope that exploits quantum effects in an atomic Bose–Einstein condensate to gain a tunable enhancement in precision. Current inertial navigation systems rely on the Sagnac effect using unentangled photons in fibre-optic systems and there are proposals for improving how the precision scales with the number of particles by using entanglement. Here we exploit a different route based on sharp resonances associated with quantum phase transitions. By adjusting the interaction between the particles and/or the shape of their trapping potential we are able to tune the width of the resonance and hence the precision of the measurement. Here we show how we can use this method to increase the overall sensitivity of a gyroscope by adjusting the system parameters as the measurement proceeds and our knowledge of the rotation improves. We illustrate this with an example where the precision is enhanced by a factor of more than 20 over the case without tuning, after 100 repetitions. Metrology schemes with tunable precision based on quantum phase transitions could offer an important complementary method to other quantum-enhanced measurement and sensing schemes.

arXiv:2110.10574Journal of Physics B Atomic Molecular and Optical PhysicsOct 6, 20216 citations

Enhanced phase estimation with coherently boosted two-mode squeezed beams and its application to optical gyroscopes

Xiao-Qi Xiao, Elisha S. Matekole, Jiankang Zhao +3 more

Quantum techniques, developed in recent decades, provide new approaches to achieving high-precision measurements beyond the classical bounds. In this paper, we theoretically demonstrate a metrology method for improving the sensitivity of the interferometric optical gyroscope, robust against the loss, by using coherent-light stimulated two-mode squeezed beams as the light source. The detection protocol is based on a simple intensity measurement, and the quantum noise is far below the shot-noise limit. The enhancement factors for different coherent light fields are analyzed in detail. Additionally, the influence of loss during the propagation in the optical path is studied, and the conditions for achieving sub-shot-noise measurement sensitivity are obtained. We also find that the phase sensitivity of the proposed gyroscope scheme becomes closer to the quantum Cramér-Rao bound with increasing of the photon number of the coherent beams.

quant-pharXiv:2607.05732Physical Review AJul 8, 20268 citations

A scheme for Sagnac effect improvement with squeezed vacuum input and homodyne detection

Kun Chen, Chen Shu-Xin, Wu Dewei +2 more

There has been much interest in improving gyroscope precision with quantum technology for realizing autonomous navigation. The laser light in coherent state cannot reach higher precision under shot-noise limit (SNL) caused by vacuum zero energy fluctuation, which restricts the further improvement of optical gyroscope precision. Quantum mechanics reckons that one unused port of the beam splitter (BS) is inputted with vacuum, which results in vacuum fluctuation, while another port is inputted with the laser light in optical gyroscope. In order to compress the vacuum fluctuation, we design an experimental scheme, in which squeezed vacuum light is used as another incident light into the unused port of Sagac interferometer in optical gyroscope. We analyze the physical process of this scheme theoretically and develop the quantum balanced homodyne detection technique to retrieve the relative phase information of Sagac interferometer output. There are two most important conditions that we should pay attention to. 1) We should ensure that the phase of local oscillator light arg(α L), the phase of coherent light arg (αc) and the angle of squeezed direction arg(μν) in the squeezed vacuum light satisfy the condition, i.e., arg (α L2)-arg (μν) = πup and arg (α L)-arg (αc) = 0 when we perform quantum balanced homodyne detection technique for the best sensitivity δφ = e-GδφSNL, where G denotes the squeezed degree; 2) only by deriving the fields from one common source can we ensure coherence among the squeezed vacuum, probe and local oscillator. Although the requirements for experimental settings are strict, we can meet the requirement with careful calibration. Numerical analysis shows that this proposed scheme provides much higher precision below SNL: both sensitivity detection limit and dynamic range grow with an exponential rate as the squeezed degree grows. The current technology for squeezed vacuum generation by using two consecutive crystals with the optic axes tilted allows us to reach a value as high as G ≈ 16 of squeezed degree. Only by inputting such squeezed vacuum light into the unused port of BS in the optical gyroscope, can we attain sensitivity detection limit and dynamic range with increment by 108. Our approach is a new scheme for improving optical gyroscope with current available technology.

Acta Physica SinicaJan 1, 20165 citations

Upper Bound on Fidelity of Classical Sagnac Gyroscope

Thomas B. Bahder

Numerous quantum mechanical schemes have been proposed that are intended to improve the sensitivity to rotation provided by the classical Sagnac effect in gyroscopes. A general metric is needed that can compare the performance of the new quantum systems with the classical systems. The fidelity (Shannon mutual information between the measurement and the rotation rate) is proposed as a metric that is capable of this comparison. A theoretical upper bound is derived for the fidelity of an ideal classical Sagnac gyroscope. This upper bound for the classical Sagnac gyroscope should be used as a benchmark to compare the performance of proposed enhanced classical and quantum rotation sensors. In fact, the fidelity is general enough to compare the quality of two different apparatuses (two different experiments) that attempt to measure the same quantity.

arXiv:1101.4634Jan 24, 20111 citation