MZI/FPI Fiber Optic Dual-parameter Sensor Based on a Double Cone and Air Cavity Structure(Invited)

This paper proposes a Mach Zehnder/Fabry Perot Interferometer(MZI/FPI)fiber sensor based on Single-mode Fiber(SMF)and Hollow-core Fiber(HCF),which has high sensitivity to temperature and lateral loads.The proposed device consists of two single-mode fiber cones formed by manually controlling the fusion splicer and an air cavity formed by fusing a section of hollow-core fiber.The structure of the sensor is a double cone cascaded air cavity.At the beginning of the design,we compared the basic transmission spectra of single cone structure and double cone structure experimentally,and therefore chose to use double cone structure and air cavity cascade.Light undergoes its first reflection at the first interface between the single-mode fiber and the air cavity structure,and its second reflection at the second interface between the air cavity structure and the single-mode fiber.The two reflected light waves produced by the two reflections form FP interference,which can be used to measure lateral loads.The transmitted light is excited through the first cone,and a portion of the core mode light is excited to the cladding,while another portion of the core mode light continues to propagate in the core.The light couples at the second cone,and the cladding mode light couples back into the core,forming MZ interference with the core mode light,which can be used to measure temperature.The use of hollow-core fiber to form an air cavity has little effect on transmitted light,while avoiding the problem of crosstalk in dual parameter measurements.By designing temperature and lateral load experiments,this article verifies the sensitivity characteristics of this sensor to temperature and lateral loads.A significant redshift phenomenon was observed in the temperature experiment.A significant redshift phenomenon also occurred in the lateral load experiment.Through wavelength demodulation,the experimental results show that the wavelength sensitivity of the sensor to temperature is 56.29 pm/℃in the range of 30℃to 80℃.The wavelength sensitivity of the sensor to lateral loads is 1.123 nm/N in the range of 0~5 N.In addition,we have prepared multiple sets of fiber optic sensors with this structure and conducted repeated experiments to verify that the sensing performance of this structure of fiber optic sensors for temperature and lateral load is relatively stable.Also,the different waist diameters of cones will have a certain impact on the transmission spectrum of MZ,while the length of the air cavity will also have a certain impact on the reflection spectrum of FP.This article lists some fiber optic sensors for dual parameter measurement of temperature and lateral load.Compared with the listed sensors,the fiber optic sensor proposed in this article has better sensitivity to temperature and lateral load.And the fiber optic sensor proposed in this article has a simple manufacturing process,low production cost,and good performance,which has certain prospects in scientific research and industrial production.

概率整形编码调制技术

随着5G通信技术的发展,多样化的应用场景对光纤通信系统的接入灵活性提出了更高的要求.概率整形是一种具有低复杂度、高灵活度的新型调制编码技术.目前,该技术已经在国内外掀起了研究的热潮,引起众多科研工作者的关注.概率整形不仅可实现灵活的宽带光接入,而且可以对超大星座尺度的正交幅度调制信号进行优化.本文介绍了笔者所在团队在概率整形方面的一系列研究成果并展开讨论,希望能为未来光纤通信系统的研究提供借鉴与依据.

麻仁胶囊联合综合护理对精神分裂症伴发便秘的效果研究

目的:观察麻仁胶囊联合以模拟跳绳为核心的综合护理干预精神分裂症伴发便秘住院患者的效果。方法:选取108例精神分裂症伴发便秘的住院患者,按照随机数字表法分为对照组和观察组各54例,对照组使用常规便秘干预护理方法,观察组在对照组的基础上给予麻仁胶囊联合综合护理,对比2组干预效果。结果:干预后,2组的排便间隔时间及排便持续时间均改善,观察组的改善幅度大于对照组(P<0.05);2组抑郁自评量表(SDS)及焦虑自评量表(SAS)评分均降低,观察组的降低幅度大于对照组(P<0.05)。对照组护理满意率为57.41%,观察组护理满意率为77.78%,差异有统计学意义(χ^2=5.115,P=0.024<0.05)。结论:利用麻仁胶囊联合综合护理干预精神分裂症住院患者,可以改善其便秘情况,缓解患者的负性情绪,提升护理满意度。