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- Keyword
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- ESPI (2)
- HOE (2)
- Holographic optical elements (2)
- Interferometry (2)
- Mode analysis (2)
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- Photopolymer (2)
- Vibrations (2)
- Acrylamide based photopolymers (1)
- Figure; Holography (1)
- Flow control Plasma flows Carbon Plasma materials processing Process monitoring and control (1)
- Holoeye LC2002 (1)
- Holographic applications (1)
- Holographic gratings (1)
- Holographic sensors (1)
- Holography (1)
- Humidity sensors (1)
- LDV (1)
- Laser Doppler vibrometry (1)
- Luminescent (1)
- Luminescent Solar (1)
- Nanocomposites (1)
- Photopolymers (1)
- Polymers; Diffusion; Interference microscopy; Surface measurements (1)
- Reflection holograms (1)
- Solar (1)
- Switchable liquid crystal devices (1)
- Twisted nematic liquid crystal spatial light modulators (1)
- Publication
Articles 1 - 9 of 9
Full-Text Articles in Physics
Real-Time Plasma Controlled Chemistry In A Two-Frequency, Confined Plasma Etcher, Vladimir Milosavljevic, Albert R. Ellingboe, Cezar Gaman, John V. Ringwood
Real-Time Plasma Controlled Chemistry In A Two-Frequency, Confined Plasma Etcher, Vladimir Milosavljevic, Albert R. Ellingboe, Cezar Gaman, John V. Ringwood
Articles
The physics issues of developing model-based control of plasma etching are presented. A novel methodology for incorporating real-time model-based control of plasma processing systems is developed. The methodology is developed for control of two dependent variables (ion flux and chemical densities) by two independent controls (27 MHz power and O2flow). A phenomenological physics model of the nonlinear coupling between the independent controls and the dependent variables of the plasma is presented. By using a design of experiment, the functional dependencies of the response surface are determined. In conjunction with the physical model, the dependencies are used to deconvolve the sensor …
A Visual Indication Of Environmental Humidity Using A Colour Changing Hologram Recorded In A Self-Developing Photopolymer, Izabela Naydenova, Raghavendra Jallapuram, Vincent Toal, Suzanne Martin
A Visual Indication Of Environmental Humidity Using A Colour Changing Hologram Recorded In A Self-Developing Photopolymer, Izabela Naydenova, Raghavendra Jallapuram, Vincent Toal, Suzanne Martin
Articles
A reflection hologram for visual indication of environmental humidity has been studied. The hologram is recorded in a self-developing photopolymer and changes colour when exposed to a change in humidity and is fully reversible. The range of colour change, reversibility and the response time of the hologram have been studied in a controlled humidity environment. Fully reversible holograms with response times from few seconds to tens of minutes have been designed. Extremely sensitive bright visual humidity indicators, capable of dramatic colour change within a few seconds of breathing on them are demonstrated.
Fabrication Of Switchable Liquid Crystal Devices Using Surface Relief Gratings In Photopolymer, Pavani Kotakonda, Izabela Naydenova, Robert Howard, Suzanne Martin, Vincent Toal
Fabrication Of Switchable Liquid Crystal Devices Using Surface Relief Gratings In Photopolymer, Pavani Kotakonda, Izabela Naydenova, Robert Howard, Suzanne Martin, Vincent Toal
Articles
Holographically recorded surface relief gratings in dry, self-developing acrylamide based photopolymer were used to fabricate two types of switchable liquid crystal (LC) device. One is an electrically switchable LC diffraction grating and the other is an electrically switchable polarization rotator. The electrically switchable diffraction grating was characterized by measuring the dependence of the intensity in the first diffracted order on the applied electric field. The polarization rotator was characterized by studying the influence of the applied electric field on the twist angle and the variation of intensity in the zero and the first orders of diffraction.
Luminescent Solar Concentrators: A Review Of Recent Results, Wilfrid G.J.H.M. Van Sark, Keith W.J. Barnham, Lenneke H. Slooff, Amanda J. Chatten, Andreas Buchtemann, Andreas Meyer, Sarah Mccormack, Rolf Koole, Daniel J. Farrell, Rahul Bose, Evert E. Bende, Antonius R. Burgers, Tristram Budel, Jana Quilitz, Manus Kennedy, Toby Meyer, C. De Mello Donega, Andries Meijerink
Luminescent Solar Concentrators: A Review Of Recent Results, Wilfrid G.J.H.M. Van Sark, Keith W.J. Barnham, Lenneke H. Slooff, Amanda J. Chatten, Andreas Buchtemann, Andreas Meyer, Sarah Mccormack, Rolf Koole, Daniel J. Farrell, Rahul Bose, Evert E. Bende, Antonius R. Burgers, Tristram Budel, Jana Quilitz, Manus Kennedy, Toby Meyer, C. De Mello Donega, Andries Meijerink
Articles
Luminescent solar concentrators (LSCs) generally consist of transparent polymer sheets doped with luminescent species. Incident sunlight is absorbed by the luminescent species and emitted with high quantum efficiency, such that emitted light is trapped in the sheet and travels to the edges where it can be collected by solar cells. LSCs offer potentially lower cost per Wp. This paper reviews results mainly obtained within the framework of the Fullspectrum project. Two modeling approaches are presented, i.e., a thermodynamic and a ray-trace one, as well as experimental results, with a focus on LSC stability.
Method For Characterization Of Diffusion Properties Of Photopolymerisable Systems, Tzvetanka Babeva, Izabela Naydenova, Suzanne Martin, Vincent Toal
Method For Characterization Of Diffusion Properties Of Photopolymerisable Systems, Tzvetanka Babeva, Izabela Naydenova, Suzanne Martin, Vincent Toal
Articles
A novel approach for measuring the diffusion coefficients in photopolymerisable materials is proposed. The method is based on studying the evolution of the surface relief profile in a single illuminated spot using an interferometric surface profiler. It is shown that the observed post-exposure swelling in the illuminated spot is due to mass-transport of monomer from the unexposed to the exposed area driven by a monomer concentration gradient set up by the monomer polymerization in the exposed area. Appropriate choice of the thickness of the studied layers ensures both lateral movement of monomer and negligible contribution from the depth. The diffusion …
Nanocomposites For Novel Holographic Applications, Izabela Naydenova, Svetlana Mintova, Suzanne Martin, Vincent Toal
Nanocomposites For Novel Holographic Applications, Izabela Naydenova, Svetlana Mintova, Suzanne Martin, Vincent Toal
Articles
Nanozeolites incorporated into photopolymerizable holographic recording materials can be used for holographic sensing, data storage, and optical systems design.
Implementation Of Phase-Only Modulation Utilizing A Twisted Nematic Liquid Crystal Spatial Light Modulator, Mohammad Mahmud, Izabela Naydenova, Vincent Toal
Implementation Of Phase-Only Modulation Utilizing A Twisted Nematic Liquid Crystal Spatial Light Modulator, Mohammad Mahmud, Izabela Naydenova, Vincent Toal
Articles
Twisted nematic liquid crystal spatial light modulators, (SLM) are widely used for amplitude modulation of light. The technique for measuring phase and amplitude modulation introduced by a twisted nematic cell is not new but the novelty here is that after characterisation of a Holoeye LC2002 TNLC device we were able to identify specific conditions that allow for its use as a pure 180 degree or more, phase modulator with little or no amplitude modulation at 514.5 nm laser wavelength. The phase shift introduced by the SLM was measured using a Mach-Zehnder interferometer. The experimentally measured and the theoretically predicted intensity …
Hoe-Based Espi Systems, Emilia Mihaylova, Viswanath Bavigadda, Raghavendra Jallapuram, Vincent Toal
Hoe-Based Espi Systems, Emilia Mihaylova, Viswanath Bavigadda, Raghavendra Jallapuram, Vincent Toal
Conference Papers
Electronic speckle pattern interferometry (ESPI) is a full-field measurement technique, capable of displaying vibrational mode shapes. Two electronic speckle pattern interferometers using reflection holographic optical elements (RHOEs) are presented. In the first ESPI system the RHOE is designed to create the speckled reference beam. A partially reflective glass plate provides illumination of the object along the normal to its surface, ensuring that the system is sensitive only to out-of-plane displacement of the object. It is demonstrated that the HOE-based system can be used for vibration measurements. Phase shifting can be implemented for fringe analysis. In the second ESPI system a …
Whole Field Out-Of-Plane Vibration Analysis With A Hoe-Based Espi System, Emilia Mihaylova, Viswanath Bavigadda, Raghavendra Jallapuram, Vincent Toal
Whole Field Out-Of-Plane Vibration Analysis With A Hoe-Based Espi System, Emilia Mihaylova, Viswanath Bavigadda, Raghavendra Jallapuram, Vincent Toal
Conference Papers
Electronic speckle pattern interferometry (ESPI) is a full-field measurement technique, capable of displaying vibrational mode shapes. A simple optical set-up for an ESPI system using a holographic optical element (HOE) is presented. The HOE is designed to create a speckled reference beam in the interferometer. A partially reflective glass plate provides illumination of the object along the normal to its surface, ensuring that the system is sensitive only to out-of-plane displacement of the object. It is demonstrated that the HOE-based system can be used for vibration measurements. Phase shifting can be implemented for fringe analysis. A big advantage of the …