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- 实验方案
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Panda type few-mode fiber capable of both mode profile and polarization maintenance
摘要： We report the design, fabrication and characterization of panda type few-mode fiber (panda-FMF) capable of both mode profile and polarization maintenance, due to the use of two applied stress rods into the conventional FMF. The panda-FMF can support six spatial modes including LP01, LP11a, LP11b, LP21a, LP21b and LP02, and each possesses two orthogonal linear polarization modes. According to the characterization results of panda-FMF, we theoretically identify that the effective refractive index (RI) difference between either two spatial or orthogonal linear polarization modes is more than 1×10-4 over the C-band. Moreover, the experimental results verify that, both mode profile and polarization of high-order radially asymmetric modes can be perfectly maintained even under severe twist rate of 1.57 rad/m.
关键词： polarization-maintaining,fiber optics,Fiber design and fabrication,fibers
更新于2025-09-23 15:21:01
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[IEEE 2019 4th Scientific International Conference Najaf (SICN) - Al-Najef, Iraq (2019.4.29-2019.4.30)] 2019 4th Scientific International Conference Najaf (SICN) - Study Evanescent-field Penetration Depth in Tapered Nano-fiber Optics
摘要： the use of etching in the fabrication of nanofiber optic (NFO) can enable the creation of thinner, longer, bundled, and strong wires. The aim of this etching methodology is to control the reduction of the core diameter and to demonstrate two different reducing methods applied to fabricate NFO. A large penetration depth of an evanescent field (EF) is the explanation of achievement for increasing a fiber-optic evanescent-field sensor (FOEFS). In general, the penetration depth (dp) of an optical fiber, stripped of its cladding, was a relation to the wavelength of the incident light, the refractive index (RI) of the surrounding medium and the incident angle on the basis of the ray-tracing model. Ray tracing analysis of tapered nano fiber optics segments and of combination taper probes make evident that the increases along the length of the taper, creating a segmented sensor with increased excitation light available at the surface for stimulating of ray transmitting. In this work, to study an NFO based on a tapered sensing probe by using the numerical analysis. The light power transmission and ultimate sensitivity of the element sensor are influenced by the incident angle, the numerical aperture (NA), core diameter, and taper ratio (TR). The TR of 0.1 and 0.7 are yield higher dp in certain regions. Then, the optimal result and the maximum dp were obtained with dp =1140 nm in TR=0.1 and a tapering length (L) of position tapering Z=40 mm.
关键词： fabricated nanofiber optics,ray tracing,tapered fiber optics,nanofiber optic sensors
更新于2025-09-23 15:19:57
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Integration of chiral cellulose nanocrystal films in silica optical fibers
摘要： Cellulose nanocrystals have attracted great attention as new “wonder” materials for photonic applications owing to their unique property of spontaneous self-assembly to form chiral nematic films. Here, the incorporation of chiral cellulose nanocrystal films on a photonic waveguide is demonstrated for the first time – in the form of integrated silica optical fibers with a helicoid nanocrystal film on their input facet. In order to achieve repeatable cholesteric ordering across the fiber core modal area, a fabrication method was developed where several optical fiber facets form part of a larger flat surface, which acts as the substrate for the planar anchoring of the cellulose nanocrystals. The resultant optical fibers exhibit significant circular dichroism (almost 40%) in transmission and act as all-fiber spectral filters. The proposed fabrication technique provides a simple, low-cost method for developing chiral silica optical fibers that remain compatible with standard telecommunication fiber technology. It is envisioned that the incorporation of cellulose nanocrystals in other optical fiber types will enable the development of a new class of fiber devices.
关键词： optical films,optical device fabrication,optical materials,optical polarization,fiber optics,optical fibers,optical fiber devices
更新于2025-09-23 15:19:57
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A Large Detection-Range Plasmonic Sensor Based on An H-Shaped Photonic Crystal Fiber
摘要： An H‐shaped photonic crystal fiber (PCF)‐based surface plasmon resonance (SPR) sensor is proposed for detecting large refractive index (RI) range which can either be higher or lower than the RI of the fiber material used. The grooves of the H‐shaped PCF as the sensing channels are coated with gold film and then brought into direct contact with the analyte, which not only reduces the complexity of the fabrication but also provides reusable capacity compared with other designs. The sensing performance of the proposed sensor is investigated by using the finite element method. Numerical results show that the sensor can work normally in the large analyte RI (na) range from 1.33 to 1.49, and reach the maximum sensitivity of 25,900 nm/RIU (RI units) at the na range 1.47–1.48. Moreover, the sensor shows good stability in the tolerances of ±10% of the gold‐film thickness.
关键词： fiber optics sensors,photonic crystal fiber,refractive index sensor,surface plasmon resonance
更新于2025-09-23 15:19:57
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Helicity Enhanced Torsion Sensor Based on Liquid Filled Twisted Photonic Crystal Fibers
摘要： A highly sensitive torsion sensor can be constructed by combining a twisted photonic crystal fiber with a liquid-filled waveguide in its air-hole cladding. The torsion sensitivity of this type of sensor is determined directly by the phase-matching conditions between the fiber core mode and the liquid waveguide mode, which can be improved by tuning the helicity (denoted by the initial twist rate, α0) of the twisted photonic crystal fiber. The enhancement mechanism of α0 on the sensitivity of the proposed torsion sensor is investigated theoretically, followed by experimental verifications, and a torsion sensitivity as high as 446 nm·mm·rad?1 can be obtained by tailoring these parameters. Experimental results show that the torsion sensitivity increases with α0 decreasing from 3.142 to 3.925 rad/mm, which are in consistence with that of the numerical predictions. The demonstrated torsion sensor is expected to contribute to the development of highly sensitive torsion-related photonic crystal fiber devices.
关键词： photonic crystal fibers,microstructure fabrication,fiber optics sensors
更新于2025-09-23 15:19:57
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Concrete Crack Monitoring Using a Novel Strain Transfer Model for Distributed Fiber Optics Sensors
摘要： In this paper, we study the strain transfer mechanism between a host material and an optical fiber. A new analytical model handling imperfect bonding between layers is proposed. A general expression of the crack-induced strain transfer from fractured concrete material to optical fiber is established in the case of a multilayer system. This new strain transfer model is examined through performing wedge splitting tests on concrete specimens instrumented with embedded and surface-mounted fiber optic cables. The experimental results showed the validity of the crack-induced strain expression fitted to the distributed strains measured using an Optical Backscattering Reflectometry (OBR) system. As a result, precise estimations of the crack openings next to the optical cable location were achieved, as well as the monitoring of the optical cable response through following the strain lag parameter.
关键词： crack,distributed strains,crack opening,wedge splitting test,fiber optics sensors,strain transfer,imperfect bonding,concrete
更新于2025-09-23 15:19:57
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Design of long period fiber grating surrounding refractive index sensor based on mode transition near phase-matching turning point
摘要： This work presents a novel design of long period fiber grating (LPFG) refractive index sensor based on mode transition near phase-matching turning point (PMTP). The dual peaks can approach to PMTP by adjusting the fiber radius, and LPFG can operate in the mode transition range by choosing the optimal film thickness. Through experiments, the LPFG based on mode transition near PMTP was fabricated by the aforesaid design, and a glycerol solution concentration monitoring test was performed to analyze its sensing properties. The results show that if the dual peaks are close to PMTP and the overlay thickness stays within the mode transition range, the sensitivity to surrounding refractive index (SRI) will be greatly improved. Compared with the regular LPFG sensors based on dual peaks resonance or the LPFG sensors based on mode transition, this LPFG has a higher sensitivity to SRI which can reach to 4900nm/RIU in the SRI range of 1.34~1.39.
关键词： Fiber optics,Thin films,Fiber optics sensors
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE 3rd Advanced Information Technology, Electronic and Automation Control Conference (IAEAC) - Chongqing, China (2018.10.12-2018.10.14)] 2018 IEEE 3rd Advanced Information Technology, Electronic and Automation Control Conference (IAEAC) - Study on diaphragm Fabry-Perot pressure sensor
摘要： The manufacture method of the diaphragm Fabry-Perot(F-P) pressure sensor was studied. The sensor formed an F-P cavity by welding the hollow fiber on the end face of the single mode fiber, and manufactured a quartz diaphragm by cutting and grinding the single mode fiber. A new fitting demodulation method is proposed, which can obtain the FP cavity’s reflectivity, the diaphragm’s outside reflectivity, the F-P cavity length and the diaphragm thickness at one time. It is highly practical for the parameter monitoring in the sensor manufacturing process. Experiments show that the sensor has high sensitivity and linearity, and has great potential application value in the field of fluid mechanics measurement.
关键词： fiber optics,curve fitting,Pressure measurement,F-P interferometer,fiber sensor
更新于2025-09-19 17:15:36
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Cascaded tilted fiber Bragg grating for enhanced refractive index sensing
摘要： We proposed and experimentally demonstrated a cascaded tilted fiber Bragg grating (TFBG) for enhanced refractive index sensing. The TFBG is UV-inscribed in series in ordinary single-mode fiber (SMF) and reduced-diameter SMF with the same tilt angle, and then excites two sets of superposed spectral combs of cladding modes. The cascaded TFBG with total length of 18 mm has a much wider wavelength range over 100 nm and narrower wavelength separation than that of a TFBG only in the SMF, enabling an enlarged range and a higher accuracy of refractive index measurement. The fabricated TFBG with the merits of enhanced sensing capability and temperature self-calibration presents great potentials in the biochemical sensing applications.
关键词： refractive index measurement,tilted fiber Bragg grating,fiber optics sensors
更新于2025-09-19 17:15:36
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[IEEE 2018 IEEE International Ultrasonics Symposium (IUS) - Kobe, Japan (2018.10.22-2018.10.25)] 2018 IEEE International Ultrasonics Symposium (IUS) - Theoretical Analysis and Design of Longitudinal Leaky SAW Device Consisting of ScA1N Film / Piezoelectric Single Crystal Substrate
摘要： Theoretical Analysis and Design of Longitudinally Pumped Erbium-Doped Fiber Amplifiers for High-Power Operation
关键词： Fiber optics,Optical amplification,Erbium-doped fiber amplifier,Longitudinal pumping,High-power operation
更新于2025-09-19 17:15:36