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- 摘要
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- 实验方案
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[IEEE 2019 Systems of Signal Synchronization, Generating and Processing in Telecommunications (SYNCHROINFO) - Russia (2019.7.1-2019.7.3)] 2019 Systems of Signal Synchronization, Generating and Processing in Telecommunications (SYNCHROINFO) - Investigation of the Influence of the Optical Fiber Structure on the Mandelstam – Brillouin Backscatter Characteristics
摘要： The influence of structure of optical fibers, varieties and concentration of ligating additives, number of layers on the behavior of the Mandelstam – Brillouin scattering in optical fibers is discussed in this paper. The results of analysis and comparison study of the results for different optical fibers are presented.
关键词： Brillouin reflectometry,optical fiber,spectrum profile,acoustic mode,Mandelstam – Brillouin scattering
更新于2025-09-11 14:15:04
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A Combined Events Recognition Scheme Using Hybrid Features in Distributed Optical Fiber Vibration Sensing System
摘要： In this paper, a high efficiency multiple events recognition scheme based on a hybrid feature extraction algorithm and a combined classifier for distributed optical fiber vibration sensing (DOFVS) system has been proposed and demonstrated. The hybrid feature vectors are extracted by using zero crossing rate, sample entropy, wavelet packet energy entropy, kurtosis, and multiscale permutation entropy. A combined classifier of support vector machine and radial basis function neural network is proposed to improve the reliability of the recognition results. The recognition result is given only when both of the two classifiers output same event types. The experimental results demonstrated that the average identification rate of five typical patterns (no intrusion, waggling the fence, climbing the fence, kicking the fence, and cutting the fence) over 97% is achieved through the combined classifier. Moreover, the whole recognition processing speed of the combined scheme is also good of real time performance, which can be limited in 1.1 s. Therefore, this kind of events recognition scheme has a quite promising application prospects in DOFVS system.
关键词： hybrid feature vectors,signal analysis,Distributed vibration sensing,events recognition,optical fiber,combined classifier
更新于2025-09-11 14:15:04
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[IEEE 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Sao Paulo, Brazil (2019.10.7-2019.10.9)] 2019 SBFoton International Optics and Photonics Conference (SBFoton IOPC) - Graphene Coplanar Capacitor for Electro-Optical Modulation
摘要： We present an all-fiber graphene electro-absorption optical modulator built onto a side-polished optical fiber in a coplanar capacitor configuration. For a maximum PMMA superstrate thickness of 1 μm and for a gap of 0.1 and 1 μm it was possible to obtain, respectively, a maximum modulation depth of 7.6 dB/mm and 5.3 dB/mm, a capacitance of 98.4 fF/mm and 63.1 fF/mm and frequencies of 16.2 GHz and 25.3 GHz. The contribution of this work is to demonstrate a low capacitance design with an optimized process fabrication for optical modulation.
关键词： graphene-based modulator,coplanar capacitor,side-polished optical fiber,electro-absorption
更新于2025-09-11 14:15:04
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[IEEE 2019 Joint Conference of the IEEE International Frequency Control Symposium anEuropean Frequency and Time Forum (EFTF/IFC) - Orlando, FL, USA (2019.4.14-2019.4.18)] 2019 Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum (EFTF/IFC) - Earthquakes detection with optical fibers
摘要： The existing optical fiber network for telecommunication, together with coherent laser interferometry techniques such as narrow-linewidth lasers and heterodyne detection, is proposed as a tool for the detection of earthquakes. Using this infrastructure, we were able to detect several earthquakes, with moment magnitude as small as 3.4 and distances to the epicenter ranging between 25 and 18500 km. Such capability is extremely relevant for the detection of earthquakes in the seas and oceans, which are today poorly covered by bulk seismometers. We propose this technique as complementary to traditional detection and show how it can be established on the existing fiber network.
关键词： optical fiber link,frequency metrology,narrow-linewidth lasers,heterodyne detection,laser interferometry
更新于2025-09-11 14:15:04
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Packaged Negative Axicon Optical Fiber Probe and Bessel Beam Interferometry for Refractive Index Measurement of Hazardous Liquid Samples
摘要： In this work, we demonstrate the packaging of an optical fiber negative axicon probe generating Bessel beam and its application in the measurement of refractive index (RI) of hazardous liquids. The negative axicon probe is placed inside cascaded capillary tube capped with a glass coverslip of RI ~1.52 and thickness ~0.15 mm. The packaged probe, connected to a broadband source through an optical circulator, is dipped in different hazardous liquid samples. The reflected light from the air-glass as well as the glass-liquid interface couples to the negative axicon probe and interferes with the reference beam generated at the air-negative axicon interface. The interference spectra recorded in a spectrometer through the circulator are analyzed applying Fast Fourier Transform (FFT). The FFT helps to separate and measure powers reflected from the different interfaces which are used to solve the Fresnel equation for estimating the RI of hazardous liquid samples, such as HCl, H2SO4 solutions. The resolution achieved is 1*10-4 ± 0.0005. The probe can be useful to measure RI of liquid samples remotely and in hazardous environmental condition.
关键词： refractive index,Bessel beam,Negative Axicon,optical fiber,hazardous liquid
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Polarization Dependance Engineering of Chalcogenide Optical Fiber Couplers
摘要： Chalcogenide (ChG) glasses are well known as key materials for the fabrication of optical fiber components compatible with optical transmission in the mid-infrared. Recently, single-mode ChG optical fiber couplers (OFCs) have been proposed for broadband coupling as well as for wavelength multi/demultiplexing [1]. From silica fibers, it has been shown that a proper engineering of fused optical fiber couplers can lead to polarization beamsplitting [2]. Here, we explore the polarization properties of single-mode OFCs made out of ChG glass. We show that by an appropriate engineering of their aspect ratio, the polarization dependence of OFCs is adjusted from highly polarization dependent down to polarization independent.
关键词： mid-infrared,polarization dependence,aspect ratio,Chalcogenide glasses,optical fiber couplers
更新于2025-09-11 14:15:04
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[IEEE 2019 Joint Conference of the IEEE International Frequency Control Symposium anEuropean Frequency and Time Forum (EFTF/IFC) - Orlando, FL, USA (2019.4.14-2019.4.18)] 2019 Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum (EFTF/IFC) - Optical Fiber Trans-national Time Transfer for Comparing Two UTC Realisations
摘要： A trans-national optical fiber time transfer link, based on the White Rabbit Precision Time Protocol has been established between the UTC timescale realizations of the Belgian Metrology Service (SMD) in Brussels, Belgium and the ESTEC Radio Navigation Laboratory in Noordwijk, The Netherlands. The link consists of a single fiber covering a span of approximately 260 km. For verification, the optical fiber time transfer is compared with GPS-based common view time transfer. The results of the two techniques agree well within the combined uncertainties. The estimated uncertainty for the optical fiber time transfer is 0.2 ns.
关键词： optical fiber,Time transfer,White Rabbit
更新于2025-09-11 14:15:04
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Theoretical and Experimental Investigation of an All-Fiber Waveguide Coupled Surface Plasmon Resonance Sensor With Au–ZnO–Au Sandwich Structure
摘要： In this paper, we proposed an all-fiber waveguide coupled surface Plasmon resonance (SPR) sensor which was designed and fabricated with Au-ZnO-Au sandwich multi-layer structure. Based on the transfer matrix method (TMM), the theoretical modeling of the proposed sensor structure was investigated. The influence of the layer thickness on the transmission spectrum of the sensor was studied numerically, in order to optimize each layer thickness, leading to sensitivity enhancement in the infrared spectral range. Meanwhile, an experimental testbed for the refractive index measurement was implemented based on the proposed all-fiber waveguide coupled SPR sensor. Using this waveguide coupled SPR sensor, the refractive index sensing was realized with a sensitivity enhancement of 7%—131% compared with conventional SPR sensors.
关键词： refractive index sensing,optical fiber,Surface plasmon resonance,waveguide coupled,sensitivity
更新于2025-09-11 14:15:04
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[IEEE 2019 IEEE Photonics Conference (IPC) - San Antonio, TX, USA (2019.9.29-2019.10.3)] 2019 IEEE Photonics Conference (IPC) - Enhanced Subwavelength Coupling and Nanofocusing with Fiber-Plasmonic Hybrid Probe
摘要： Metallic nanowires supporting surface plasmon polaritons can localize optical fields at nanoscale for near-field imaging. In this paper, we propose a photonic-plasmonic probe for nanoscale light confinement. The linearly polarized fiber mode is asymmetrically coupled to radial plasmons to create hot-spot at the tip apex.
关键词： nano-antenna,surface plasmon polaritons,optical fiber,near-field microscopy,mode conversion
更新于2025-09-11 14:15:04
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Photobiomodulation By Diffusing Optical Fiber on Spinal Cord:A Feasibility Study in piglet model
摘要： Aim: Previous studies on spinal cord injury (SCI) have confirmed that percutaneous photobiomodulation (PBM) therapy can ameliorate immunoinflammatory responses at sites of injury, accelerate nerve regeneration, suppress glial scar formation, and promote the subsequent recovery of locomotor function. The current study was performed to evaluate a large-animal model employing implanted optical fibers to accurately irradiate targeted spinal segments. The method’s feasibility and irradiation parameters that do not cause phototoxic reaction were determined, and the methodology of irradiating the spinal cord with near-infrared light was investigated in detail. Methods: A diffusing optical fiber was implanted above the T9 spinal cord of Bama miniature pigs and used to transfer near-infrared light (810 nm) onto the spinal cord surface. After daily irradiation with 200, 300, 500, or 1000 mW for 14 days, both sides of the irradiated area of the spinal cord were assessed for temperature changes. The condition of the spinal cord and the position of optical fiber were investigated by magnetic resonance imaging (MRI), and different parameters indicating temperature increases or phototoxicity were measured on the normal spinal cord surface due to light irradiation (i.e., heat shock responses, inflammatory reactions, and neuronal apoptosis), and the animals’ lower-limb neurological function and gait were assessed during the irradiation process. Results: The implanted device was stable inside the freely moving animals, and light energy could be directly projected onto the spinal cord surface. The screening of different irradiation parameters preliminary showed that direct irradiation onto the spinal cord surface at 200 and 300 mW did not significantly increase the temperature, stress responses, inflammatory reactions and neural apoptosis, whereas irradiation at 500 mW slightly increased these parameters, and irradiation at 1000 mW induced a significant temperature increase, heat shock, inflammation and apoptosis responses. HE staining of spinal cord tissue sections did not reveal any significant structural changes of the tissues compared to the control group, and the neurological function and gait of all irradiated animals were normal. Conclusion: In this study, we established an in-vivo optical fiber implantation method, which might be safe and stable and could be used to directly project light energy onto the spinal cord surface. This study might provide a new perspective for clinical applications of PBM in acute SCI.
关键词： diffusing optical fiber,Bama miniature pigs,Photobiomodulation,Spinal cord
更新于2025-09-11 14:15:04