Author Affiliations
Abstract
1 College of Information Science and Engineering, Northeastern University, Shenyang 110819, China
2 Hebei Key Laboratory of Micro-Nano Precision Optical Sensing and Measurement Technology, Qinhuangdao 066004,China
3 College of Electronics and Information Engineering, Sichuan University, Chengdu 610064, China
In this paper, a new concept of forward-pumped random Raman fiber laser (RRFL)-based liquid refractive index sensing is proposed for the first time. For liquid refractive index sensing, the flat fiber end immersed in the liquid can act as the point reflector for generating random fiber lasing and also as the sensing head. Due to the high sensitivity of the output power of the RRFL to the reflectivity provided by the point reflector in the ultralow reflectivity regime, the proposed RRFL is capable of achieving liquid refractive index sensing by measuring the random lasing output power. We theoretically investigate the effects of the operating pump power and fiber length on the refractive index sensitivity for the proposed RRFL. As a proof-of-concept demonstration, we experimentally realize high-sensitivity half-open short-cavity RRFL-based liquid refractive index sensing with the maximum sensitivity and the sensing resolution of –39.88 W/RIU and 2.507 5 × 10-5 RIU, respectively. We also experimentally verify that the refractive index sensitivity can be enhanced with the shorter fiber length of the RRFL. This work extends the application of the random fiber laser as a new platform for highly-sensitive refractive index sensing in chemical, biomedical, and environmental monitoring applications, etc.
Fiber optic sensors refractive index measurements fiber lasers Rayleigh scattering stimulated Raman scattering Photonic Sensors
2024, 14(1): 240121
1 南京信息工程大学电子与信息工程学院，江苏 南京 210044
2 南京信息工程大学江苏省大气环境与装备技术协同创新中心，江苏 南京 210044
提出并制备了一种基于法布里-珀罗干涉仪（FPI）和反共振（AR）效应的光纤温湿度传感器。将单模光纤（SMF）和端面固化了聚酰亚胺（PI）的带涂层无芯光纤（NCF）插入非封闭硅管两端构建FPI，利用具有相似光程的空气腔和空气-PI混合腔产生光谱叠加的游标效应，显著提高相对湿度检测灵敏度。NCF包层的光和部分折射进丙烯酸树脂涂层的光耦合形成AR，利用温度引起涂层折射率的改变导致AR非透射波长产生漂移，实现对温度的高灵敏度测量。实验结果表明：在10%~80%的相对湿度范围内，相对湿度灵敏度为510.25 pm/%；在26~35 ℃的温度范围内，温度灵敏度可达-4.48 nm/℃。该传感器具有成本低、灵敏度高的优点，在生物医学、健康监测等方面具有重要的应用价值。
传感器 光纤传感器 温湿度 游标效应 法布里-珀罗干涉仪 反共振
Author Affiliations
Abstract
1 Photonics Research Centre, University of Malaya, Kuala Lumpur 50603, Malaysia
2 Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia
3 Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ, UK
4 School of Mathematics, Computer Science and Engineering, City University of London, London EC1V 0HB, UK
A new and easy-to-fabricate strain sensor has been developed, based on fiber Bragg grating (FBG) technology embedded into a thermoplastic polyurethane filament using a 3-dimensional (3D) printer. Taking advantage of the flexibility and elastic properties of the thermoplastic polyurethane material, the embedding of the FBG provides durable protection with enhanced flexibility and sensitivity, as compared to the use of a bare FBG. Results of an evaluation of its performance have shown that the FBG sensors embedded in this way can be applied effectively in the measurement of strain, with an average wavelength responsivity of 0.013 5 nm/cm of displacement for tensile strain and –0.014 2 nm/cm for compressive strain, both showing a linearity value of up to 99%. Furthermore, such an embedded FBG-based strain sensor has a sensitivity of ~1.74 times greater than that of a bare FBG used for strain measurement and is well protected and suitable for in-the-field use. It is also observed that the thermoplastic polyurethane based (TPU-based) FBG strain sensor carries a sensitivity value of ~2.05 times higher than that of the polylactic acid based (PLA-based) FBG strain sensor proving that TPU material can be made as the material of choice as a “sensing” pad for the FBG.
Fiber-optic sensors fiber Bragg grating 3D printing technology multiple-point strain measurement Photonic Sensors
2022, 12(3): 220302
1 太原工业学院 电子工程系，山西 太原 030008
2 中北大学 信息与通信工程学院，山西 太原 030051
3 信息探测与处理山西省重点实验室，山西 太原 030051
基于级联光栅的微振动传感器是一种典型的微振动信号测量方案，然而由于光信号在级联光栅中经过多次透射和反射，导致光谱信噪比差、成分复杂等问题。基于此，文中提出一种结合经验模态分解和切比雪夫滤波技术的光谱信号优化算法。首先，将传感器原始光谱通过经验模态分解得到一系列本征模函数；其次，利用所提出的自适应滤波方法，确定包含反射峰成分的本征模函数阶数，并对其进行切比雪夫低通滤波；最后，将滤波器输出进行重构，即得到优化后的传感器光谱。使用振幅为±8 mV、频率为500 Hz的微振动激励信号进行实验验证。结果表明：文中所提出算法可以较好地还原激励源发出的微振动信号，相比传统方法精度提高87.5%以上。
光纤传感器 振微动 算法 光谱 fiber optic sensors micro-vibration algorithm spectrum 红外与激光工程
2022, 51(7): 20210645
1 南京航空航天大学 1. 空间光电探测与感知工信部重点实验室
2 物理学院
3 航天学院, 南京 211106
布里渊光时域光纤传感是一种连续分布式光纤传感技术, 可广泛用于获取沿传感光纤的温度和应变等物理量分布。如何提高布里渊散射信号的测量和处理速度, 以满足工程应用中的快速测量需求, 是布里渊光纤传感领域研究者的主要关注点之一。文章通过分析传统布里渊光时域光纤传感系统的耗时来源, 综述了近年来基于频率调制、功率谱测量、图像处理去噪和布里渊谱拟合方法改进等布里渊光时域传感中的快速测量技术研究进展。
光纤传感器 布里渊散射 载波调制 图像处理 神经网络 fiber optic sensors Brillouin scattering carrier modulation image processing neural networks
强激光与粒子束
2022, 34(5): 059001
Author Affiliations
Abstract
1 Fiber Optics Research Center (FORC), Key Laboratory of Optical Fiber Sensing & Communications, University of Electronic Science and Technology of China, Chengdu 611731, China
2 Chengdu Aircraft Industrial Group Co., Ltd., Chengdu 610092, China
This paper reviews a wide variety of fiber-optic microstructure (FOM) sensors, such as fiber Bragg grating (FBG) sensors, long-period fiber grating (LPFG) sensors, Fabry-Perot interferometer (FPI) sensors, Mach-Zehnder interferometer (MZI) sensors, Michelson interferometer (MI) sensors, and Sagnac interferometer (SI) sensors. Each FOM sensor has been introduced in the terms of structure types, fabrication methods, and their sensing applications. In addition, the sensing characteristics of different structures under the same type of FOM sensor are compared, and the sensing characteristics of the all FOM sensors, including advantages, disadvantages, and main sensing parameters, are summarized. We also discuss the future development of FOM sensors.
Fiber-optic sensors Fabry-Perot fiber Bragg grating long period grating Mach-Zehnder interferometer Michelson interferometer Sagnac interferometer Photonic Sensors
2021, 11(2): 227
Author Affiliations
Abstract
1 School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
2 National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
Recently, microfiber-optic sensors with high sensitivity, fast response times, and a compact size have become an area of interest that integrates fiber optics and nanotechnology. Distinct advantages of optical microfiber, such as large accessible evanescent fields and convenient configurability, provide attractive benefits for micro- and nano-scale optical sensing. Here, we review the basic principles of microfiber-optic sensors based on a broad range of microstructures, nanostructures, and functional materials. We also introduce the recent progress and state-of-the-art in this field and discuss the limitations and opportunities for future development.
Optical microfiber optical sensing fiber-optic sensors microstructures Photonic Sensors
2021, 11(1): 45
Author Affiliations
Abstract
State Key Laboratory of High Performance Complex Manufacturing, College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China
A phase-shifted fiber Bragg grating (PS-FBG) based on a microchannel was proposed and realized by combining the point-by-point scanning method with chemical etching. The PS-FBG is composed of a fiber Bragg grating (FBG) and a microchannel through the fiber core. The microchannel can introduce phase shift into the FBG. What is more important is that it exposes the fiber core to the external environment. The phase shift peak is sensitive to the liquid refractive index, and it shows a linear refractive index response wavelength and intensity sensitivity of 2.526 nm/RIU and -111 dB/RIU, respectively. Therefore, such gratings can be used as sensors or tunable filters.
fiber Bragg grating microchannel structure phase shift fiber optic sensors Chinese Optics Letters
2021, 19(3): 030602
1 西安交通大学电力设备电气绝缘国家重点实验室, 陕西 西安 710049
2 全球能源互联网研究院电力传感技术研究所, 北京 102209
3 伦敦玛丽女王大学工程和材料学学院, 伦敦 E1 4NS
光纤传感技术的长距离传输和分布式检测的优势在电缆线路的状态监测领域具有很大的应用价值。利用相位敏感型光时域反射仪(Φ-OTDR)对电缆接头故障诊断中的局部放电进行研究。瑞利散射相干光信号具有随机特性,其方差变量可作为弱小超声信号的检测量。在电缆局部放电实验中,将5个光纤环传感器绕制在电缆接头上特定的超声监测点,以此来验证Φ-OTDR系统的分布式定位检测能力。实验同时对比了局部放电的电测法和光纤声测法的信号特征,并利用压电传感器来校正5个光纤环传感器的位置,以验证Φ-OTDR分布式光纤超声传感器在局部放电测量中的特性。
光纤光学 光纤传感器 光时域反射仪 瑞利散射
