相干反馈增强型量子混合干涉仪  

Coherent Feedback Enhanced Quantum Hybrid Interferometer

作　　者：刘攀[1] 于志飞 黄文峰 吴媛[1] 陈丽清[1] LIU Pan;YU Zhi-fei;HUANG Wen-feng;WU Yuan;CHEN Li-qing(School of Physical and Electronic Sciences,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学物理与电子科学学院,上海200241

出　　处：《量子光学学报》2023年第2期30-40,共11页Journal of Quantum Optics

基　　金：国家自然科学基金(11874152,12104161);上海市科技英才扬帆计划资助(19YF1414300);上海市教育委员会科研创新计划重大项目(202101070008E00099)。

摘　　要：本文在理论上提出了一种由非线性分束器和线性合束器构成的量子混合干涉仪,其中非线性分束器是由非线性参量过程结合量子压缩源的线性相干反馈构成,用于提高量子混合干涉仪相位灵敏度。具体而言,光学参量放大输出的光束与量子压缩源线性反馈至输入端,获得一对纠缠度可控的双模压缩光束,结合线性合束器,构建反馈型量子混合干涉仪。结果表明,相比于无反馈量子混合干涉仪,本方案通过调节反馈强度至合适区间,可以在增加相敏光子数实现干涉信号强度提高的同时,增强两干涉臂之间纠缠度进而减小干涉噪声。此外,将压缩真空态作为反馈环结构的输入态,能够进一步降低探测信号的噪声。因此,本方案从以上三个方面有效地提升混合干涉仪的测量灵敏度,甚至在有损的情况下,相比于无反馈情形,该反馈型量子混合干涉仪仍具有更好的相位灵敏度,表现出更好的抗损能力,有望应用在量子精密测量领域。In this paper,a quantum hybrid interferometer consisting of a nonlinear beam splitter and a linear beam splitter is proposed in theory.The nonlinear beam splitter is composed of a nonlinear parametric process combined with linear coherent feedback of a quantum squeezed source to improve the phase sensitivity of the quantum hybrid interferometer.Specifically,the optical parametric amplifier(OPA)output beam and the quantum squeezed source are linearly fed back to the input end to obtain a pair of dual-mode squeezed beams with controllable entanglement.Combined with the linear beam combination,the feedback quantum hybrid interferometer is constructed.The results show that compared with the non-feedback quantum hybrid interferometer,the scheme can increase the number of phase-sensitive photons by adjusting the feedback intensity to an appropriate range to improve the interference signal intensity and enhance the degree of entanglement between the two interference arms to reduce the interference noise.In addition,the squeezed vacuum state as the input state of the feedback loop structure can further reduce the noise of the detection signal.Therefore,this scheme can effectively improve the measurement sensitivity of the hybrid interferometer from the above three aspects.Even in the case of lossy,the feedback quantum hybrid interferometer compared with without feedback still has better phase sensitivity and anti-damage ability,which is expected to be applied in the field of quantum metrology.

关 键 词：相干反馈 量子纠缠 干涉仪 相位灵敏度 

分 类 号：O431[机械工程—光学工程]