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Full-Text Articles in Physics
Fabrication And Characterisation Of Large Area, Uniform And Controllable Surface Relief Patterns In Photopolymer Material, Owen Kearney, Izabela Naydenova
Fabrication And Characterisation Of Large Area, Uniform And Controllable Surface Relief Patterns In Photopolymer Material, Owen Kearney, Izabela Naydenova
Conference Papers
As the risk of antibiotic resistant pathogens increases, development of convenient point of care devices is essential. Such devices would help avoid infection – ensure cleanliness of environments and assist in bacteria analysis. The ultimate aim of the research presented here is to develop a compact, cost effective, easy to use optical device which is capable of detecting and quantifying bacteria in an aqueous sample. The surface relief patterns have a dual role, they provide a diffracted light signal, and control the adhesion of the bacteria to the surface. The strength of the diffracted signal is expected to provide a …
Development Of Photopolymer Material With Improved Dynamic Range And Sensitivity, Brian Rogers, Izabela Naydenova, Suzanne Martin
Development Of Photopolymer Material With Improved Dynamic Range And Sensitivity, Brian Rogers, Izabela Naydenova, Suzanne Martin
Conference Papers
In this study the effect of the concentration of acrylamide and the influence of different initiators in a photopolymer composition for holographic recording of diffraction gratings is investigated. Light manipulating Holographic Optical Elements (HOEs) have a number of characteristics which can be optimised for different roles. However, at the core of these devices is the refractive index modulation that has been created in the material during recording. Typically higher refractive index modulation will enable greater diffraction efficiency. Solar concentrating HOEs can particularly benefit from material that experiences higher refractive index modulation. For a solar concentrator to have a high acceptance …
N-Isopropylacrylamide-Based Photopolymer For Holographic Recording Of Thermosensitive Transmission And Reflection Grating, Tatsiana Mikulchyk, Suzanne Martin, Izabela Naydenova
N-Isopropylacrylamide-Based Photopolymer For Holographic Recording Of Thermosensitive Transmission And Reflection Grating, Tatsiana Mikulchyk, Suzanne Martin, Izabela Naydenova
Articles
In recent years, functionalized photopolymer systems capable of holographic recording are in great demand due to their potential use in the development of holographic sensors. This work presents a newly developed Nisopropylacrylamide(NIPA)-based photopolymer for holographic recording in reflection and transmission modes. The optimized composition of the material is found to reach refractive index modulation of up to 5 10-3 and 1.6 10-3 after recording in transmission and reflection mode, respectively. In addition to fulfilling the requirements for holographic recording materials, the NIPA-based photopolymer is sensitive to temperature and has lower toxicity than acrylamide-based photopolymers. Possible application of the …
Robust Fast Direct Integral Equation Solver For Quasi-Periodic Scattering Problems With A Large Number Of Layers, Min Hyung Cho, Alex H. Barnett
Robust Fast Direct Integral Equation Solver For Quasi-Periodic Scattering Problems With A Large Number Of Layers, Min Hyung Cho, Alex H. Barnett
Dartmouth Scholarship
We present a new boundary integral formulation for time-harmonic wave diffraction from two-dimensional structures with many layers of arbitrary periodic shape, such as multilayer dielectric gratings in TM polarization. Our scheme is robust at all scattering parameters, unlike the conventional quasi-periodic Green’s function method which fails whenever any of the layers approaches a Wood anomaly. We achieve this by a decomposition into near- and far-field contributions. The former uses the free-space Green’s function in a second-kind integral equation on one period of the material interfaces and their immediate left and right neighbors; the latter uses proxy point sources and small …
Using Acrylamide Based Photopolymers For Fabrication Of Holographic Optical Elements In Solar Energy Applications, Hoda Akbari, Izabela Naydenova, Suzanne Martin
Using Acrylamide Based Photopolymers For Fabrication Of Holographic Optical Elements In Solar Energy Applications, Hoda Akbari, Izabela Naydenova, Suzanne Martin
Articles
A holographic device is under development that aims to improve light collection in solar cells. The aim is to explore the potential of using photopolymer Holographic Optical Elements (HOE) to collect light from a moving source, such as the sun, and re-direct it for concentration by a holographic lens.. A working range of 45 degrees is targeted for such a device to be useful in solar applications without tracking. A photopolymer HOE is capable of efficiently re-directing light, but the angular selectivity of a single grating is usually of the order of one degree at the thicknesses required for high …
Design And Study Of Acrylamide-Based Photopolymer Holographic Optical Elements For Solar Application, Hoda Akbari, Izabela Naydenova, Manus Kennedy, John Doran, Suzanne Martin
Design And Study Of Acrylamide-Based Photopolymer Holographic Optical Elements For Solar Application, Hoda Akbari, Izabela Naydenova, Manus Kennedy, John Doran, Suzanne Martin
Conference Papers
Abstract: Solar concentrators can be used to reduce the cost of photovoltaic electrical power generation by collecting incident solar radiation from a given aperture area and transmitting the energy to a reduced area. In doing so, the overall cost of power (Wp) can be reduced as less area of photovoltaic is required. This paper will discuss Holographic Solar Concentrators fabricated in an acrylamide photopolymer , describing the optical recording process and showing how the fabricated HOE’s can be used in solar concentrator devices. Preliminary lifetime studies are also discussed.
New Non-Toxic Holographic Photopolymer Material, Dervil Cody, Izabela Naydenova, Emilia Mihaylova
New Non-Toxic Holographic Photopolymer Material, Dervil Cody, Izabela Naydenova, Emilia Mihaylova
Articles
There is an increasing need for environmentally friendly holographic recording materials which can be produced in bulk with little risk to the health of workers in manufacturing. This is why the development of non-toxic photopolymer materials is crucial, and has attracted attention in recent years. Composition and preliminary characterization of a new non-toxic photopolymer material are presented. It operates well at a range of spatial frequencies, and achieves diffraction efficiencies and refractive index modulation comparable to the known acrylamide-based photopolymers.
Replay At Optical Communications Wavelengths Of Holographic Gratings Recorded In The Visible, Vincent Toal, Maurice Whelan, Alberto Volcan, Izabela Naydenova, Suzanne Martin
Replay At Optical Communications Wavelengths Of Holographic Gratings Recorded In The Visible, Vincent Toal, Maurice Whelan, Alberto Volcan, Izabela Naydenova, Suzanne Martin
Conference Papers
In this paper we report on holographic diffraction gratings recorded at visible light wavelength, which can be probed at telecommunication wavelengths. The recording material is an easily prepared, self-processing photopolymer, all of whose components are water soluble. Transmission gratings of various types, namely unslanted, slanted, totally internally reflecting and Bragg gratings were all fabricated. Diffraction efficiencies at telecommunications wavelengths compare favourably with those obtained in visible light.