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- 摘要
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- 实验方案
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Turbidity and RI Dependency of a Polymer Optical Fiber-Based Chromatic Sensor
摘要： An in-line and real time chromatic sensor for liquids based on plastic optical fiber was developed. It uses an air gap, fiber to fiber, transmission principle. Its dependency to turbidity and refractive index is studied and characterized. This information will provide the necessary knowledge for future implementation of more complex auto-compensations routines. Due to the predictable behavior of the sensor to variations of turbidity and refractive index, it is shown that a posterior compensation could be applied for the discrimination of color. The real-time color sensor can be used in different turbid liquids and contain different refractive indices.
关键词： colorimeter,optical fiber,chromatic sensor,refractive index,turbidity,in-line
更新于2025-09-12 10:27:22
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Construction of Multi-soliton Solutions of the <i>N</i> -Coupled Hirota Equations in an Optical Fiber <sup>*</sup>
摘要： This work aims to study the ?? -coupled Hirota equations in an optical fiber under the zero boundary condition at infinity. By analyzing the spectral problem, a matrix Riemann–Hilbert problem on the real axis is strictly established. Then, by solving the presented matrix Riemann–Hilbert problem under the constraint of no reflection, the bright multi-soliton solutions to the ?? -coupled Hirota equations are explicitly gained.
关键词： multi-soliton solutions,optical fiber,Riemann–Hilbert problem,?? -coupled Hirota equations
更新于2025-09-12 10:27:22
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Signal analysis and processing method of transmission optical fiber hydrogen sensors with multi-layer Pd–Y alloy films
摘要： To detect hydrogen leakage as soon as possible, researchers try their best to improve the sensitivity and response speed of the hydrogen sensor. However, the sensitivity and response speed are two contradictive parameters. It is hard to improve them simultaneously. The transmission optical fiber sensor with multi-layer films is the only structure which can increase the response speed and enhance sensibility simultaneously. However, because of its special structure, the output signal of the sensor often drifts. This paper designed an in-situ observation system to study the reason why the sensor drifts. The in-situ observation system found a periodic oscillation pattern for the transmission spectrum which depends on the wavelength of the light source. The transmission spectrum patterns of the sensor with multi-layer PalladiumeYttrium (PdeY) alloy films under different hydrogen concentrations were analyzed. The source of drift error induced by the wavelength shift of the light source was confirmed. By using a moving average algorithm, the error characteristics of the sensor were analyzed and simulated. The results show that the increased sweep width of the laser can effectively restrain the signal drift of sensors. Particularly, when the sweep width of the laser just is the integer multiples of the period of the transmission spectrum, the suppression of the oscillation was optimal. A sensor with a wavelength-swept laser was implemented. For the sweep width of 1.1 nm, the maximum wavelength sensitivity of the sensor is only 0.046 mv/pm. The wavelength drift error is significantly less than that without signal processing. The sensor has achieved a detection limit of 0.05% which is identical to the sensor with the frequency-stabilized laser. Finally, a design principle was proposed to optimize the light source parameters and structure parameters of the probe for the high stability of the optical fiber hydrogen sensor.
关键词： Stability design,Optical fiber hydrogen sensor,Signal analysis and processing
更新于2025-09-12 10:27:22
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Experimental realization of Fermi-Pasta-Ulam-Tsingou recurrence in a long-haul optical fiber transmission system
摘要： The integrable nonlinear Schr?dinger equation (NLSE) is a fundamental model of nonlinear science which also has important consequences in engineering. The powerful framework of the periodic inverse scattering transform (IST) provides a description of the nonlinear phenomena modulational instability and Fermi-Pasta-Ulam-Tsingou (FPUT) recurrence in terms of exact solutions. It associates the complex nonlinear dynamics with invariant nonlinear spectral degrees of freedom that may be used to encode information. While optical fiber is an ideal testing ground of its predictions, maintaining integrability over sufficiently long distances to observe recurrence, as well as synthesizing and measuring the field in both amplitude and phase on the picosecond timescales of typical experiments is challenging. Here we report on the experimental realization of FPUT recurrence in terms of an exact space-time-periodic solution of the integrable NLSE in a testbed for optical communication experiments. The complex-valued initial condition is constructed by means of the finite-gap integration method, modulated onto the optical carrier driven by an arbitrary waveform generator and launched into a recirculating fiber loop with periodic amplification. The measurement with an intradyne coherent receiver after a predetermined number of revolutions provides a non-invasive full-field characterization of the space-time dynamics. The recurrent space-time evolution is in close agreement with theoretical predictions over a distance of 9000 km. Nonlinear spectral analysis reveals an invariant nonlinear spectrum. The space-time scale exceeds that of previous experiments on FPUT recurrence in fiber by three orders of magnitude.
关键词： finite-gap solutions,nonlinear Schr?dinger equation,nonlinear spectral analysis,Fermi-Pasta-Ulam-Tsingou recurrence,optical fiber transmission
更新于2025-09-12 10:27:22
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Micro-Cantilever Displacement Detection Based in Optical Fiber Tip
摘要： This work demonstrates the potential of combining a microsphere with a tip for the functionality of the contact sensor. This sensor consists of a tip aligned with the fiber core and a microsphere, which appears during tip formation. This new structure was produced using the electric arc machine. The sensor operation consists of the variation of the tip curvature, which causes a variation of the optical paths and, consequently, a change in the output signal. The study of this micro-cantilever consisted of an exploration of the contact mode. In addition, the sensor was characterized by temperature, which shows very low sensitivity and vibration. This last characterization was performed with two configurations parallel and perpendicular to the oscillating surface. The perpendicular case showed higher sensitivity and has an operating band of 0 Hz to 20 kHz. In this configuration, for frequencies up to 2 Hz, the intensity varies linearly with the frequencies and with a sensitivity of 0.032 ± 0.001 (Hz?1). For the parallel case, the operating band was from 1.5 kHz to 7 kHz.
关键词： detection,physic,cantilever,microsphere,optical fiber structure,optic,sensor,vibration,tip
更新于2025-09-12 10:27:22
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Treatment of Trichloroethylene with Photocatalyst-Coated Optical Fiber
摘要： In this present study, we investigated the effect of photocatalyzation on the degradation of trichloroethylene (TCE) in the aqueous phase by a photocatalyst-coated plastic optical fiber (POF). Two light-emitting diodes (LEDs) with low light intensity were used as the light source and TiO2 and ZnO were used as photocatalysts, which were characterized by scanning electron microscope (SEM) and UV-Vis diffuse reflectance spectroscopy (DRS). The para-chlorobenzoic acid (pCBA) was used as the hydroxyl radical probe for kinetic study and for the calculation of hydroxyl radical conversion rate (ROH,UV ). Experimental results show that POF coated with TiO2 exhibited higher degradation efficiency of TCE in basic solution, but POF coated with ZnO performed better in acidic solution. The increase of coating times resulted in the decrease in degradation efficiency of TCE due to increased thickness of the photocatalyst layer. The enhancement of light intensity contributed to the improvement of photocatalytic treatment efficiency. The ROH,UV for TiO2 and ZnO coated POF increased from 2 × 103 to 8 × 103 M s cm2 mJ?1 and from 8 × 102 to 2 × 103 M s cm2 mJ?1, respectively, as the pH increased from 4 to 10.
关键词： trichloroethylene (TCE),optical fiber,photocatalysis,groundwater,hydroxyl radical
更新于2025-09-12 10:27:22
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Optical Trapping and Manipulation Using Optical Fibers
摘要： An optical trap forms a restoring optical force field to immobilize and manipulate tiny objects. A fiber optical trap is capable of establishing the restoring optical force field using one or a few pieces of optical fiber, and it greatly simplifies the optical setup by removing bulky optical components, such as microscope objectives from the working space. It also inherits other major advantages of optical fibers: flexible in shape, robust against disturbance, and highly integrative with fiber-optic systems and on-chip devices. This review will begin with a concise introduction on the principle of optical trapping techniques, followed by a comprehensive discussion on different types of fiber optical traps, including their structures, functionalities and associated fabrication techniques. A brief outlook to the future development and potential applications of fiber optical traps is given at the end.
关键词： Optical manipulation,Optical trapping,Fiber optical traps,Optical fiber
更新于2025-09-11 14:15:04
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Optical Fiber-Based Sensing, Measuring, and Implementation Methods for Slope Deformation Monitoring: A Review
摘要： Slope instabilities are a common occurrence in hilly areas, mine, and dam region, which bring a grave threat to the safety of transportation business and human life. The effective slope monitoring methods and instruments can provide information on the current deformation and historical trends, which is important scientific information for researchers to analyze slope stability and provide a timely warning to the public. Optical fiber sensors (OFS) have attracted many researchers to explore due to their have unique advantages in comparison with conventional electronic based sensing technologies, including immunity to electromagnetic interference, remote transmission, easy integration and high sensitivity. This paper presents an overview of the latest development and application of OFS based slope deformation monitoring from two aspects: 1) Fiber Bragg grating (FBG) based sensing and monitoring technology; 2) Distributed optical fiber sensors (DOFS) Brillouin Optical Time Domain Reflectometry (BOTDR) and Brillouin Optical Time Domain Analysis (BOTDA) for slope monitoring. Meanwhile, current challenges in implementing the OFS-based slope monitoring technology are discussed.
关键词： Optical fiber sensors,Distributed optical fiber sensors,Fiber Bragg grating,Slope deformation monitoring
更新于2025-09-11 14:15:04
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Unified Formalism for Erbium-Doped Fiber Amplifiers and Lasers
摘要： A comprehensive and integrated exact analytical formalism is presented for erbium-doped fiber amplifiers and lasers (EDFALs) in one single configuration based on solutions of a system of rate and propagation equations represented by a homogenously broadened four band transition scheme while incorporating amplified spontaneous emission and excited state absorption effects. The formalism, under steady-state conditions, concurrently provides considerable insight into physical characteristics underlying phenomena pertinent to EDFALs and allows precise evaluation of behavior exhibited by EDFALs through a judicious selection of pump intensity and fiber length in standard eye-safe low-erbium concentration uniformly doped mono-mode silica glass fibers in co- and counter- propagating directions appropriate to signal, pump and ASE regimes.
关键词： analytical modeling,erbium-doped fiber amplifiers,optical fiber communication,erbium-doped fiber lasers
更新于2025-09-11 14:15:04
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Dispersion Management in Hybrid Optical Fibers
摘要： We report a new fiber concept, which is a hybrid design between classical step-index and photonic crystal fibers (PFCs). The proposed structure has a centrally located Ge doped core surrounded by a set of smaller microinclusions distributed in the cladding. In numerical investigations, we demonstrate that such a combination allows to arbitrarily shape the dispersion profile in a 1 μm wide spectral range while reducing the confinement losses with respect to air-hole PCFs exhibiting similar dispersion characteristics. We present simple guidelines for optimizing the structure. Finally, as a proof of concept, we show an adequately designed fiber which, even though is based on fused silica glasses and is an all-solid construction, is still capable of providing flat and all-normal dispersion characteristics (-37 ± 2.5 ps/nm/km) in broadband range from 1.3 μm up to 2.15 μm and ultra-flat (-37 ± 0.2 ps/nm/km) for wavelength values from 1.5 μm to 1.9 μm.
关键词： Optical fiber dispersion,Optical fiber
更新于2025-09-11 14:15:04