论文标题
Fabry-Pérot纤维腔射流折射率通过线宽跟踪折射的PT-对称区域
Fabry-Pérot fiber cavity refractive index sensing via linewidth tracking in the broken PT-symmetric region
论文作者
论文摘要
在特殊点附近运行的平均时间（PT）对称光传感器最近引起了很多吸引力，在测量小扰动方面具有无与伦比的高灵敏度。过去，大多数PT对称传感器都是基于跟踪由于扰动诱导的PT-对称系统两个下腔之间耦合强度的变化而产生的模式分解的。我们设计了一个线性纤维Fabry-Pérot和耦合的腔传感器，该传感器量身定制，可在断裂的PT对称区域中运行。我们探索了一种新的感应度量，即，该模式的线宽变化是扰动诱导的PT-对称系统亚腔内损耗的变化的函数。在我们提出的传感器中，两个下腔之间的耦合强度保持不变。在数学公式的支持下，我们发现空腔共振的全宽度最大最大（FWHM）表现出对折射率（RI）的平方根依赖性在其中一个亚腔中变化。所提出的纤维腔折射率传感器的最大灵敏度为$ 2.26 \ times10^7 $ ghz/riU，最低检测极限为$ 10^{ - 9} $ riU，大大超过了可比较的腔传感器，主张构成相同的射精折射率变化，并损失损失设置。
Parity-time (PT) symmetric optical sensors operating around exceptional points have recently gained much attraction, offering an unparalleled high sensitivity in measuring small perturbations. In the past, most of the PT-symmetric sensors have been based on tracking the mode-splitting that arises due to a perturbation-induced change in coupling strength between two subcavities of the PT-symmetric system. We design a linear fiber Fabry-Pérot and coupled cavities sensor, tailored to operate in the broken PT-symmetric region. We explore a new sensing metric-that is, the mode's linewidth change as a function of perturbation-induced changes in the loss within one of the subcavities of the PT-symmetric system. The coupling strength between the two subcavities remains unchanged in our proposed sensor. Supported by a mathematical formulation, we find that the full-width-half-maximum (FWHM) of the cavity resonances exhibits a square root dependence on the refractive index (RI) change in one of the subcavities. The proposed fiber cavity refractive index sensor has a maximum sensitivity of $2.26\times10^7$ GHz/RIU and a lowest detection limit of $10^{-9}$ RIU, widely outperforming the comparable cavity sensors subject to the same refractive index change, gain, and loss settings.
