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Full-Text Articles in Physics
Hologram-Based Humidity Indicator For Domestic And Packaging Applications, Izabela Naydenova, Raghavendra Jallapuram, Vincent Toal, Suzanne Martin
Hologram-Based Humidity Indicator For Domestic And Packaging Applications, Izabela Naydenova, Raghavendra Jallapuram, Vincent Toal, Suzanne Martin
Conference Papers
A passive indicator for Relative Humidity based on a photopolymer recorded hologram has been developed. The indicator works on the principle that the wavelength reconstructed by a reflection hologram is dependent on the spacing between the fringe planes of the hologram. As the Relative Humidity changes, the hologram swells or shrinks and the apparent colour of the reconstructed image changes. The response time, operational range and reversibility of the indicator have been studied in a controlled humidity environment. Response times from less than a minute to tens of minutes depending on the holograms physical properties have been measured. Indicators with …
A Compact Electronic Speckle Pattern Interferometry System Using A Photopolymer Reflection Holographic Optical Element, Guntaka Tulasi Sridhar Reddy, Raghavendra Jallapuram, Vincent Toal, Izabela Naydenova, Suzanne Martin, Svetlana Mintova
A Compact Electronic Speckle Pattern Interferometry System Using A Photopolymer Reflection Holographic Optical Element, Guntaka Tulasi Sridhar Reddy, Raghavendra Jallapuram, Vincent Toal, Izabela Naydenova, Suzanne Martin, Svetlana Mintova
Conference Papers
A simple and compact electronic speckle pattern interferometry system using a reflection holographic optical element is presented. The reflection holographic optical element is recorded on an acrylamide based photopolymer formulated and prepared at the Centre for Industrial & Engineering Optics. Light intensity of 40mW/cm2 with an exposure time of 60 seconds was used in fabricating the holographic optical element. The vibration mode patterns of a 4 cm diameter thin circular sheet of brass metal attached to a 4 cm diameter paper cone loud speaker are presented.