基于光纤光栅器件的聚合物微环传感信号解调

基于啁啾光纤光栅和长周期光栅,文章提出一种应用于聚合物微环传感器和微环传感器阵列的信号解调方法。通过调整长周期光栅的峰值波长来匹配感测范围,从而实现线性边沿滤波。该系统由全光纤器件组成,这种解调可以达到31 pm的高分辨率。双通道系统中,每个通道的波长带宽为2.4 nm

双包层光纤芯径与位置影响吸收效率的研究

为了提高双包层光纤结构中泵浦光耦合进纤芯的效率,文章首先探索了常折射率内包层光纤中芯径与内包层尺寸比对吸收效率的影响。然后对端泵入射光进行建模,研究了纤芯偏心距的优化。数值模拟结果表明,当偏心距为R-r时,即纤芯位于内包层边缘时,吸收效率最高。文章还阐述了渐变折射率内包层对耦合效率的影响

基于单纤拉锥M-Z干涉仪的折射率传感器

在单模光纤中级联两个对称缓锥,中间段去除涂覆层,包层作为传感臂对外界折射率敏感,实验上形成M-Z（马赫-曾德尔）干涉仪。对锥区光场进行分析,当锥腰半径为25!m时,光纤内模场半径达到最大值,约为14.8!m。当锥形光纤锥腰半径为12.5!m、过渡区为5 mm、锥间隔为131 mm时,耦合与合波效果最佳,此时传感臂可检测的酒精浓度范围为0100%,折射率和波长偏移存在很好的线性关系,灵敏度为-120nm/RIU。该传感器具有插入损耗低、性能稳定和抗干扰能力强等优点,可应用于酒厂酒精度检测和水质监测等领域

长周期光纤光栅表面等离子体共振增强传感器

针对光纤表面等离子体共振传感普遍存在强度脆弱、灵敏度偏低及等离子体激发效率低下的问题，文章将长周期光纤光栅作为辅助平台，研究了表面等离子体共振传感器增强灵敏度的途径。在光纤光栅表面传感区域热蒸发一层金膜，通过调谐输入光纤光栅部位的偏振光模式来实现对外传感性能的增强。选用氯化钠溶液作为外界折射率感应物质，通过软件进行模拟仿真，仿真结果表明，镀金膜前后，横磁波和横电波的透射功率在空气中分别衰减了4.3和0.3 dB，在溶液中分别衰减了5.3和2.2 dB。在1.335~1.372溶液折射率变化范围内，两种偏振光源的折射率灵敏度分别提升了18.7和12.9 nm/RIU

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies