基于纠缠数态和奇偶校验的光纤陀螺仪相位测量性能分析

Analysis of phase measurement performance of fiber optic gyroscope based on entangled state and parity measurement

针对多光子最大纠缠NOON态难以直接作为光纤陀螺仪的双模输入态,且当输出态的光子数差算符为0时标准光强差测量方案将失效的问题,提出了一种基于纠缠光子数态和奇偶校验方案的双端口输入/输出光纤陀螺仪结构。阐述了基于关联数态的纠缠光纤陀螺仪的工作原理和奇偶校验测量方法,首次推导了双模纠缠光子数态光纤陀螺仪的相位估计误差公式,并将双光子、四光子双模纠缠数态输入与具有相同光子数(光功率)的最大纠缠NOON态输入以及经典相干态输入的Sagnac相位测量精度进行了对比。理论分析表明,利用纠缠光子数态(不一定是最大纠缠态)结合奇偶校验测量可以突破散粒噪声限制而达到海森堡极限,所提方法仅需对量子光学陀螺仪的输出端进行奇偶校验即可实现,是增强光学陀螺仪输出精度的一种新方法。

In order to solve the problem that the maximum entangled state NOON is difficult to directly serve as the two-mode input state of the fiber optic gyroscope, and the standard light intensity difference measurement scheme will fail when the photon number difference operator of the output state is 0, a two-port input/output fiber optic gyroscope structure based on the number state and parity measurement scheme of entangled photons is proposed. The basic principle and parity measurement method of fiber optic gyroscope based on entangled number state are expounded, and the phase estimation error formula of the two-mode entangled number state in fiber optic gyroscope is deduced for the first time. And the accuracy of Sagnac phase measurement with the input of two-photon, four-photon entangled number state, the maximum entangled state and the classical coherent state are compared under the same number of photons(optical power). It shows that the use of entangled number state(not necessarily the maximum entangled state)combined with the parity measurement can break the shot noise limit and reach the Heisenberg limit after theoretical analysis. The proposed method only needs to perform parity measurement on the output of the quantum optical gyroscope, which is a new method to enhance the output of the optical gyroscope.