- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - How to Amplify Light in an Unfilled Hollow Core Optical Fiber
摘要： Optical amplification in a hollow core fiber is typically realised by filling the fiber with a gas and exploiting its active properties. In contrast, here we explore the theoretical possibility of achieving light amplification in an unfilled hollow core antiresonant fiber. In order to do so, we propose and discuss a hollow fiber design based on a combination of resonant and anti-resonant elements within the cladding area.
关键词： fiber properties,fiber design and fabrication,microstructured fibers
更新于2025-09-16 10:30:52
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Depth-resolved fiber photometry with a single tapered optical fiber implant
摘要： Fiber photometry is increasingly utilized to monitor fluorescent sensors of neural activity in the brain. However, most implementations are based on flat-cleaved optical fibers that can only interface with shallow tissue volumes adjacent to the fiber. We exploit modal properties of tapered optical fibers (TFs) to enable light collection over an extent of up to 2 mm of tissue and multisite photometry along the taper. Using a single TF, we simultaneously observed distinct dopamine transients in dorsal and ventral striatum in freely moving mice performing a simple, operant conditioning task. Collection volumes from TFs can also be engineered in both shape and size by microstructuring the nonplanar surface of the taper, to optically target multiple sites not only in the deep brain but, in general, in any biological system or organ in which light collection is beneficial but challenging because of light scattering and absorption.
关键词： neural activity,tapered optical fibers,dopamine transients,fiber photometry,multisite photometry
更新于2025-09-16 10:30:52
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Investigation of UV Irradiation Response of Optical Fiber Sensors for Radiation Dosimetry
摘要： In this work, the investigation of radiation response for modified cladding multimode optical fibres exposed to UV radiation (N2 Laser) in terms of Radiation-Induced Attenuation (RIA) had been presented. The optical fibres were tapered to 65 and 60 μm then dipped into (5wt % of Germanium to modify the cladding region. By exposing these fibres to different energies of UV irradiation, the transmission spectra were online monitored and recorded every ten seconds to analyze the attenuation changes with the increasing of the radiation dose. The experimental results revealed two points: the first point is that the sensor undergoes the RIA effect which is resulted from the interaction between the radiation and the dopant material, and the second point shows that the sensitivity increases as the diameter of the sensor decrease. From these outcomes, we can conclude that such a sensor can be employed in different dosimetry applications.
关键词： Radiation Dosimeters,Radiation-Induced Absorption,Optical Fiber Sensors,Germanium Doped Optical Fibers
更新于2025-09-16 10:30:52
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Luminescent solar concentrators based on melt-spun polymer optical fibers
摘要： Luminescent solar concentrators (LSCs) collect incoming sunlight and direct it to a smaller-area photovoltaic cell. In the presented work, form factor and illumination angle-dependent performance of LSCs consisting of bi-component melt-spun fibers is demonstrated. Three thermoplastic polymers act as dispersing host material for the luminescent dye Lumogen Red 305 (LR305). Molecular dynamics simulations provide numerical access to Hildebrand solubility parameters, which are an estimate for the mixing compatibility of dye with polymer matrix. Actual emission intensity measurements from material samples are compared to Monte Carlo ray tracing simulations. Some samples show an increased absorption, which led to the hypothesis that there exist optically passive dye aggregates if the dispersion is not optimal. The best-performing polymer/dye pair is identified and used to melt-spin fibers. Geometrically defined bundles of LSC fibers are studied in a scenario of white light illumination and variation of illumination-angle. This experiment simulates a theoretical daily course-of-sun illumination in absence of atmospheric effects. We report optical conversion efficiencies of the prepared LSCs between 2% and 15%, depending on illumination angle and bundle geometry.
关键词： Polymer optical fibers,Melt spinning,Energy harvesting,Luminescent solar concentrators
更新于2025-09-16 10:30:52
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Steady State X-Ray Radiation Induced Attenuation in Canonical Optical Fibers
摘要： So-called canonical optical fibers are samples especially designed to highlight the impact of some manufacturing process parameters on the radiation responses. Thanks to the results obtained on these samples, it is thus possible to define new procedures to better control the behaviors of optical fibers in radiation environments. In the present work, we characterized the responses, under steady state X-rays, of canonical samples representative of the most common fiber types differing by their core-dopants: pure silica, Ge, Al and P. Their radiation induced attenuation (RIA) spectra were measured online at both room temperature (RT) and liquid nitrogen temperature (LNT), in the energy range [~0.6 - ~3.0] eV (~2100 nm - ~410 nm), highlighting the RIA growth kinetics during the fiber exposure up to an accumulated dose of ~200 Gy(SiO2) at a constant dose rate of 100 mGy/s at RT. At LNT, the deposited doses varied between 100 and 180 Gy, with a time dependent dose rate. In order to understand the origin of the excess losses and the difference between the RIA spectral shapes observed at the two temperatures, a spectral decomposition of the optical losses has been performed using a set of Gaussian absorption bands related to the already known point defects. As a result, if the RIA in the visible domain is quite well understood, the knowledge on RIA origin in the near-IR remains incomplete, justifying new and deeper studies to clarify the fibers response under steady state irradiation.
关键词： point defects,radiation effects,attenuation,pure silica core and doped optical fibers,canonical samples
更新于2025-09-16 10:30:52
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Polymer-fiber-coupled field-effect sensors for label-free deep brain recordings
摘要： Electrical recording permits direct readout of neural activity but offers limited ability to correlate it to the network topography. On the other hand, optical imaging reveals the architecture of neural circuits, but relies on bulky optics and fluorescent reporters whose signals are attenuated by the brain tissue. Here we introduce implantable devices to record brain activities based on the field effect, which can be further extended with capability of label-free electrophysiological mapping. Such devices reply on light-addressable potentiometric sensors (LAPS) coupled to polymer fibers with integrated electrodes and optical waveguide bundles. The LAPS utilizes the field effect to convert electrophysiological activity into regional carrier redistribution, and the neural activity is read out in a spatially resolved manner as a photocurrent induced by a modulated light beam. Spatially resolved photocurrent recordings were achieved by illuminating different pixels within the fiber bundles. These devices were applied to record local field potentials in the mouse hippocampus. In conjunction with the raster-scanning via the single modulated beam, this technology may enable fast label-free imaging of neural activity in deep brain regions.
关键词： light-addressable potentiometric sensors,polymer fibers,deep brain recordings,label-free,field-effect
更新于2025-09-16 10:30:52
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Simultaneous determination of proteins in microstructured optical fibers supported by chemometric tools
摘要： A new perspective on the relevant problem—creating simple, rapid, and efficient protein sensors based on microstructured optical fibers using a simple homogeneous analysis format—was proposed. Commercially available long-period grating hollow core microstructured optical fibers (LPG HCMOF) were used to determine bovine serum albumin (BSA) and albumin from chicken eggs (OVA) in binary mixtures as well as immunoglobulin G (IgG) in the presence of BSA and OVA. LPG HCMOF transmission spectra allowed the detection of both BSA and OVA up to 10 mg/mL with LOD as low as 0.1 and 0.8 μg/mL, respectively. Partial least squares regression (PLS) was utilized for modeling of LPG HCMOF spectral data and quantitative analysis of BSA, OVA, total protein, and IgG in binary and ternary mixtures. Rather high coefficients of determination (R2) and low root mean square error for the calibration (RMSEC) (15%) and prediction (RMSEP) (20%) were obtained for all PLS models. The proposed approach was tested in the analysis of BSA in spiked horse blood hemolyzed (HBH). The results demonstrated the functionality of the proposed approach and offered the opportunity for the creation of a wide range of sensors for protein determination in complex mixtures.
关键词： Chemometrics,Partial least squares regression,Protein determination,Long-period grating fiber,Microstructured optical fibers
更新于2025-09-16 10:30:52
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Recent Advances in Inhibited-Coupling Guiding Hollow-Core Optical Fibers
摘要： In this talk, we report on recent developments on inhibited-coupling guiding hollow-core optical fibers ranging from the understanding of the guidance mechanism to application fields. We show that a deep understanding of the cladding properties of those fibers allow to obtain fibers with optimized properties. In particular, we demonstrate that, by adequately designing and controlling the fiber physical parameters, one can obtain ultralow loss fibers for the ultraviolet, visible and infrared ranges. Additionally, we show that convenient alterations in the fiber cladding can modify the fiber mode loss hierarchy allowing it to act as a mode shaper, and polarization discriminator.
关键词： hollow-core fibers,fiber optics,photonic-crystal fibers
更新于2025-09-12 10:27:22
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Nonlinear Fiber Optics || Pulse propagation in fibers
摘要： For an understanding of the nonlinear phenomena in optical ?bers, it is necessary to consider the theory of electromagnetic wave propagation in dispersive nonlinear media. The objective of this chapter is to obtain a basic equation that governs propagation of optical pulses in single-mode ?bers. Section 2.1 introduces Maxwell’s equations and important concepts such as the linear and nonlinear parts of the induced polarization and the frequency-dependent dielectric constant. The concept of ?ber modes is introduced in Section 2.2 where the single-mode condition is also discussed. Section 2.3 considers the theory of pulse propagation in nonlinear dispersive media in the slowly varying envelope approximation with the assumption that the spectral width of the pulse is much smaller than the frequency of the incident radiation. The numerical methods used to solve the resulting propagation equation are discussed in Section 2.4.
关键词： electromagnetic wave propagation,dispersive nonlinear media,numerical methods,nonlinear phenomena,optical fibers,single-mode fibers,fiber modes,pulse propagation,dielectric constant,induced polarization,Maxwell’s equations
更新于2025-09-12 10:27:22
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Nonlinear Fiber Optics || Multimode fibers
摘要： Multimode fibers were first used for nonlinear optics during the 1970s because most optical fibers available at that time supported multiple modes. The situation changed in the 1980s when single-mode fibers were commercialized in view of their telecommunication applications. The interest in multimode fibers re-surfaced after 2005, partly motivated by their use for space-division multiplexing in optical communication systems. As a byproduct of this interest, the nonlinear effects in multimode fibers have been studied extensively since 2010. This chapter covers recent advances in a systematic fashion. Three types of multimode fibers are introduced in Section 14.1, where we also discuss modes supported by them. Section 14.2 extends theory of Section 2.3 to obtain a set of coupled nonlinear equations for various fiber modes. These equations are used in Sections 14.3 to discuss modulation instability and soliton formation in multimode fibers. The focus of Section 14.4 is on the intermodal nonlinear effects that transfer energy among the modes. The spatio-temporal effects are discussed in Section 14.5 with emphasis on spatial beam cleanup and supercontinuum generation through multimode fibers. Section 14.6 is devoted to the nonlinear phenomena in multicore fibers.
关键词： modulation instability,spatio-temporal effects,spatial beam cleanup,soliton formation,multimode fibers,multicore fibers,supercontinuum generation,nonlinear optics,space-division multiplexing,intermodal nonlinear effects
更新于2025-09-12 10:27:22