1,720,992 research outputs found
Near-diffraction-limited supercontinuum generation in a cladding-pumped nonlinear fiber converter
No full textThrough nonlinear scattering including stimulated Raman scattering and beam cleanup, a pulsed multimode pump beam is converted into a nearly diffraction-limited supercontinuum extending from 1 to 2 µm in a passive cladding-pumped nonlinear fiber converter
Tandem-pumped ytterbium-doped aluminosilicate fiber amplifier with low quantum defect
No full textWe show theoretically that a quantum-defect below 1% is possible in tandem-pumped Yb-doped aluminosilicate fibers operating off the gain peak. Experimentally, we reach a quantum defect of 2% and a slope efficiency of 90% or more
Suspended-core holey fiber for evanescent-field sensing
No full textA simple fabrication technique for a silica suspended-core holey fiber design is presented that features a higher air-filling fraction than most holey fibers, making it ideal for evanescent-field-sensing applications. The holes in the fiber are defined through mechanical drilling of the preform, which is a significantly quicker and more straightforward approach to the customary stacking method. During the draw, the shape of the holes are manipulated so that the final fiber design approximates that of an air-suspended rod with three fine struts supporting the core. Modeling reveals that the modal overlap is greater than 29% at 1550 nm for a core diameter of 0.8 µm, which is significantly higher than any previously reported index-guiding structure used for sensing. A basic gas sensor is demonstrated using acetylene as the sensing medium and the results are reported
Novel fiber fabrication methods benefit fiber lasers
No full textNew modified chemical vapor deposition (MCVD)-based in-situ solution doping and chelate-in-crucible deposition techniques are improving the optical fibers from which fiber lasers are manufactured
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
First demonstration of direct UV written Bragg gratings in collapsed fibre planar samples
No full textFirst demonstration of planar Bragg gratings UV written into collapsed fibre planar samples with >200µm cladding thickness is presented. Multiple gratings were written across the sample profile to accurately determine core layer flatness and uniformity
Modification of spectroscopic properties of Bismuth doped silica fiber by post-fabrication process and different fabrication methods
No full textThe spectroscopic properties of pristine and H2-loaded MCVD based Bi-doped aluminosilicate fibers were investigated. Also, the properties of Bi-doped fiber, fabricated by powder-in-tube method, have been compared to MCVD based Bi fiber
UV-written Bragg gratings in a flat-fiber platform as a bending and twisting sensor
No full textHigh demand on structural health monitoring has encouraged the development of smart structure geometries to be more effective and competitive [1]. One of the technologies that has been integrated into these structures is the fiber Bragg grating (FBG) [2]. The FBG is a mature technology that has seen many applications, particularly the field of sensing where it has many advantages such as immunity to electromagnetic field, long lifetime, high sensitivity, lightweight and low loss. There are several types of optically based physical sensors. Most of which are fabricated in a standard dimension silica optical fiber which due to its cylindrical structure are unable to independently measure twist. Here we demonstrate a bending and twist sensor fabricated in a flat-fiber substrate. A Y-splitter and a series of Bragg gratings along the 50 mm length provides a differential signal providing distinction between bend and twist within the sample
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