ORCID Profile
0000-0002-0403-9004
Current Organisations
University of Manchester
,
Manchester Metropolitan University
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Publisher: Springer Science and Business Media LLC
Date: 27-03-2020
DOI: 10.1038/S42005-020-0326-2
Abstract: A solar-pumped laser (SPL) that converts sunlight directly into a coherent and intense laser beam generally requires a large concentrating lens and precise solar tracking, thereby limiting its potential utility. Here, we demonstrate a fully-planar SPL without a lens or solar tracking. A Nd 3+ -doped silica fiber is coiled into a cylindrical chamber filled with a sensitizer solution, which acts as a luminescent solar collector. The body of the chamber is highly reflective while the top window is a dichroic mirror that transmits incoming sunlight and traps the fluorescence emitted by the sensitizer. The laser-oscillation threshold was reached at a natural sunlight illumination of 60% on the top window. Calculations indicated that a solar-to-laser power-conversion efficiency could eventually reach 8%. Such an SPL has potential applications in long-term renewable-energy storage or decentralised power supplies for electric vehicles and Internet-of-Things devices.
Publisher: Wiley
Date: 02-05-2019
DOI: 10.1002/PIP.3133
Publisher: The Optical Society
Date: 17-12-2018
DOI: 10.1364/OL.44.000029
Publisher: AIP Publishing
Date: 03-10-2016
DOI: 10.1063/1.4963912
Abstract: We designed and fabricated an anti-reflection surface of hexagonal arrays of round-head silicon nanopillars. The measurements show a significant reduction in reflectivity across a broad spectral range. However, we then grew a conformal titanium dioxide coating via atomic layer deposition to achieve an extremely low weighted average reflection of 2.1% over the 460–1040 nm wavelength range. To understand the underlying reasons for the reduced reflectance, the simulations were conducted and showed that it is due to strong forward scattering of incident light into the silicon substrate. The calculated normalized scattering cross section demonstrates a broadband distribution feature, and the peak has a red-shift to longer wavelengths. Finally, we report two-dimensional weighted average reflectance as a function of both wavelength and angle of incidence and present the resulting analysis contour map.
Publisher: The Optical Society
Date: 21-04-2017
DOI: 10.1364/OE.25.00A502
Publisher: Elsevier BV
Date: 11-2018
Publisher: Wiley
Date: 06-05-2021
Abstract: Solar‐pumped lasers (SPLs) typically couple sunlight into the laser cavity using focusing optics and solar tracking. Luminescent solar concentrators (LSC) are an alternative, fully planar, scalable pump source that can concentrate diffuse light. For liquid LSC‐based SPLs, reflective cavities have been used to trap light and pump a Nd 3+ ‐doped silica fiber. Here, three solid‐state LSC‐based SPL designs, in addition to the reflective cavity making use of total internal reflection, are analyzed by ray‐tracing simulations. Results are compared to a liquid LSC reference, also used for validating simulations. Substituting the liquid‐state LSC for a solid‐state LSC (with the fiber placed inside) allows a 7‐fold enhancement of the gain coefficient, corresponding to a 30‐fold enhancement of the laser output power. An additional 4‐fold increase of the output power is possible with a fiber of kilometers length. These results show a roadmap for realizing SPLs with output powers on the order of 2.8 W m −2 under terrestrial sunlight, while keeping an identical reflective cavity used for the liquid LSC design. In addition, room‐temperature operation should be possible with certain solid LSC designs, and the necessity for a reflective cavity comprised of costly dielectric mirrors may be relieved.
Publisher: Optica Publishing Group
Date: 08-05-2020
DOI: 10.1364/OE.392246
Abstract: All-inorganic perovskites exhibit interesting properties and unprecedented stability compared to organic-inorganic hybrid lead halide perovskites. This work focuses on depositing and characterizing cesium lead bromide (CsPbBr 3 ) thin films and determining their complex optical constants, which is a key requirement for photovoltaic device design. CsPbBr 3 thin films are synthesized via the solution method followed by a hot-embossing step to reduce surface roughness. Variable angle spectroscopic ellipsometry measurements are then conducted at three angles (45°, 55°, and 65°) to obtain the ellipsometric parameters psi ( Ψ ) and delta ( Δ ). For the present model, bulk planar CsPbBr 3 layer is described by a one-dimensional graded index model combined with the mixture of one Tauc-Lorentz oscillator and two Gaussian oscillators, while an effective medium approximation with 50% air void is adopted to describe surface roughness layer. The experimental complex optical constants are finally determined in the wavelength range of 300 to 1100 nm. Furthermore, as a design ex le demonstration, the simulations of single-junction CsPbBr 3 solar cells are conducted via the finite-difference time-domain method to investigate the properties of light absorption and photocurrent density.
Publisher: Wiley
Date: 23-01-2012
DOI: 10.1111/J.1523-1739.2011.01813.X
Abstract: Increased education of consumers can be an effective tool for conservation of commercially harvested marine species when product labeling is accurate and allows an informed choice. However, generic labeling (e.g., as white fish or surimi) and mislabeling of seafood prevents this and may erode consumer confidence in seafood product labels in general. We used DNA barcoding to identify the species composition of two types of convenience seafood (i.e., products processed for ease of consumption): fish fingers (long pieces of fish covered with bread crumbs or batter, n = 241) and seafood sticks (long pieces of cooked fish, n = 30). In products labeled as either white fish or surimi, four teleost species were present. Less than 1.5% of fish fingers with species-specific information were mislabeled. Results of other studies show substantially more mislabeling (e.g., >25%) of teleost products, which likely reflects the lower economic gains associated with mislabeling of convenience seafood compared with whole fillets. In addition to species identification, seafood product labels should be required to contain information about, for ex le, harvesting practices, and our data indicate that consumers can have reasonable confidence in the accuracy of the labels of convenience seafood and thus select brands on the basis of information about current fisheries practice.
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 2019
Publisher: Wiley
Date: 07-04-2020
Publisher: Wiley
Date: 27-01-2023
Abstract: A phosphor‐particle‐loaded microlens array on a polymer substrate offers an attractive unclonable anticounterfeiting label design. A random pattern of bright emission points is created due to the random coincidences of light focused by a microlens with an underlying phosphor microparticle. The change of the bright point patter with the angle of the incident light (owing to a shift in the locations of the focal points) makes the labels unclonable. This work examines the authentication of such labels using a single smartphone. The smartphone flashlight provides illumination whereas the camera is used for detection (optical filters prevent capture of scattered source light). A 196‐bit binary string is created from the captured images to identify which lenses in the 14 × 14 array create bright emission points for a given position of the smartphone. The classification of test and reference images as matching or not is achieved with % confidence, as is a 1 cm tolerance for the positioning accuracy of the smartphone. Moreover, authentication is possible for different distances between flash and camera provided this is less than 3 cm. In summary, the present work quantifies the good potential of the microlens array microphosphor unclonable label concept for authentication using a smartphone.
Publisher: Optica Publishing Group
Date: 20-07-2023
DOI: 10.1364/OE.496268
Abstract: We have developed a fully planar solar-pumped fiber laser using a solid-state luminescent solar collector (LSC). This laser does not use any focusing device, such as a lens or mirror thus, it can lase without tracking the sun. Our developed device with an aperture of 30 cm emits 15 mW, corresponding to an optical-to-optical conversion efficiency of 0.023% and a collection efficiency of 0.21 W/m 2 . A 12-fold improvement over a previously developed liquid LSC is achieved by combining the total internal reflection of the solid-state LSC with dielectric multilayer mirrors. The observed laser power is in good agreement with that predicted via numerical simulation, demonstrating the effectiveness of our proposed method.
Publisher: American Chemical Society (ACS)
Date: 30-08-0014
Abstract: Advanced optical concepts, making use of tailored microstructured front cover glasses, promise to reduce the losses encountered with encapsulated solar modules. However, implementing optical concepts into the conventional architecture of encapsulated solar modules and simultaneously maintaining high durability represent a severe technological challenge. The liquid glass technique offers a route to meet this challenge by enabling the implementation of these optical concepts directly into the durable front cover glass of solar modules. In this work, we demonstrate for the first time two showcases of texturing fused silica front cover glass, using the facile liquid glass technique: (I) multifunctional microcone textures that reduce front-side reflection losses by ∼80% compared to a planar reference, which correlates to an increase in short-circuit current density of encapsulated planar monocrystalline silicon heterojunction solar cells by 2.9 mA cm
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Carly Fletcher.