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Step-index profile

About: Step-index profile is a research topic. Over the lifetime, 3104 publications have been published within this topic receiving 53199 citations.


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Journal ArticleDOI
TL;DR: The proposed refractive index sensor constructed by a short section of single eccentric hole-assisted dual-core fiber spliced between two single-mode fibers has outstanding advantages, such as simple fabrication, good mechanical strength, and excellent microfluidic channel, and will be of importance in biological detection, chemical analysis, and environment monitoring.
Abstract: We propose a novel and simple in-fiber refractive index sensor based on resonant coupling, constructed by a short section of single eccentric hole-assisted dual-core fiber (SEHADCF) spliced between two single-mode fibers. The coupling characteristics of the SEHADCF are calculated numerically. The strong resonant coupling occurs when the fundamental mode of the center core phase-matches to that of the suspended core in the air hole. The effective refractive index of the fundamental mode of the suspended core can be obviously changed by injecting solution into the air hole. The responses of the proposed devices to the refractive index and temperature are experimentally measured. The refractive index sensitivity is 627.5 nm/refractive index unit in the refractive index range of 1.335–1.385. The sensor without solution filling is insensitive to temperature in the range of 30–90°C. The proposed refractive index sensor has outstanding advantages, such as simple fabrication, good mechanical strength, and excellent microfluidic channel, and will be of importance in biological detection, chemical analysis, and environment monitoring.

25 citations

Journal ArticleDOI
TL;DR: In this paper, the dependence of Nb2O5 content on thermal, structural and optical properties were investigated by thermal analysis (DSC), Raman spectroscopy, UV-Visible absorption, M-Lines and Z-scan techniques.
Abstract: In this study we present the production and characterization of Pb2P2O7–Nb2O5 glasses and optical fibers. The dependence of Nb2O5 content on thermal, structural and optical properties were investigated by thermal analysis (DSC), Raman spectroscopy, UV–Visible absorption, M-Lines and Z-scan techniques. Glass transition temperature (Tg) increased linearly with Nb2O5 content up to 60 mol%, while thermal stability against crystallization (ΔT) reached a maximum value of 225 °C at 40 mol% of Nb2O5. Raman spectra showed a significant structural change by the insertion of NbO6 octahedral units in the glass network. The increase of Nb2O5 concentration shifts the glasses absorption edge to lower energies, and also increases the linear refractive indexes (n0) due to the high polarizability of niobium atoms and formation of non-bridging oxygen. Similarly to n0, an increase in the positive values of nonlinear refractive indexes was observed using Z-Scan technique with increase of Nb2O5 content, based on structural changes caused by the replacement of Pb2P2O7 instead Nb2O5. The average of n2 values at 500–1500 nm raised from 2.2 × 10− 19 to 3.8 × 10− 19 m2/W, when the Nb2O5 content was increased from 10 to 60 mol%. Lastly, a core-cladding preform was produced by suction method and the optical fiber drawn. The sample containing 40 mol% of Nb2O5 was used for presenting the highest thermal stability against crystallization and n0 values > 2 from green to near-infrared wavelengths. Multimode step index fiber with good core circularity and concentricity was produced and the optical losses were determined by cut-back method at visible and near-infrared ranges.

25 citations

Journal ArticleDOI
TL;DR: In this article, a highly sensitive H-shape subwavelength plasmonic metasurface is demonstrated for refractive index sensor at near-infrared wavelengths using finite difference time domain simulation.
Abstract: In this report, using finite difference time domain simulation, a highly sensitive H-shape subwavelength plasmonic metasurface is demonstrated for refractive index sensor at near-infrared wavelengths Numerical simulations show that optical transmission and reflection properties of such H-shape slit metamaterial depend significantly on the refractive index of the surrounding medium The studies reveal that an index change of 05 results in a resonant frequency shift of nearly 600 nm, which is about 1200 nm shift per refractive index unit (RIU) The detection accuracy of ∼00035 RI for every 5 nm resonance frequency shift can be achieved The frequency shift is explained on the basis of inductor capacitor (LC) model of the H-unit

25 citations

Journal ArticleDOI
Haiyang Wang1, Xin Yan1, Shuguang Li1, Guowen An1, Xuenan Zhang1 
08 Oct 2016-Sensors
TL;DR: The sensor proposed has significant advantages in the field of biomolecule detection as it provides a wide-range of detection with high sensitivity and the highest sensitivity can be up to 22,983 nm/RIU(refractive index unit) when the analyte refractive index is 1.41.
Abstract: A refractive index sensor based on dual-core photonic crystal fiber (PCF) with hexagonal lattice is proposed. The effects of geometrical parameters of the PCF on performances of the sensor are investigated by using the finite element method (FEM). Two fiber cores are separated by two air holes filled with the analyte whose refractive index is in the range of 1.33–1.41. Numerical simulation results show that the highest sensitivity can be up to 22,983 nm/RIU(refractive index unit) when the analyte refractive index is 1.41. The lowest sensitivity can reach to 21,679 nm/RIU when the analyte refractive index is 1.33. The sensor we proposed has significant advantages in the field of biomolecule detection as it provides a wide-range of detection with high sensitivity.

25 citations

Patent
14 Feb 2008
TL;DR: In this paper, a light guiding core and a transparent and/or translucent jacket made of glass are used to produce a laterally emitting step index fiber, which contains oxides, metals, diamond-like carbon and glass ceramic particles.
Abstract: The index fiber has a light guiding core (1) and a transparent and/or translucent jacket (2) made of glass. The core and the jacket include refractive indexes, respectively. A discrete scattering zone (3) located between the core and the jacket is made of glass. Scattering particles are embedded in the scattering zone. The scattering zone includes a refractive index, which differs from the refractive index of the jacket. The particles contain oxides, metals, diamond-like carbon and/or glass ceramic particles. Glass in which scattering centers are embedded is an arsenic-lead silicate glass. An independent claim is also included for a method for producing a laterally emitting step index fiber.

25 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202318
202236
20219
202011
201913
201814