Raghavendra Jallapuram

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Investigations of polymerization rates in an acrylamide-based photopolymer are presented. The polymerization rate for acrylamide and methylenebisacrylamide was determined by monitoring the changes in the characteristic vibrational peaks at 1284 and 1607 cm(-1) corresponding to the bending mode of the CH bond and CC double bonds of acrylamide and in the(More)
Results from the investigation of the diffusion processes in a dry acrylamide-based photopolymer system are presented. The investigation is carried out in the context of experimental research on optimization of the high-spatial-frequency response of the photopolymer. Tracing the transmission holographic grating dynamics at short times of exposure is(More)
A laser Doppler vibrometer (LDV) is described in which holographic optical elements are used to provide the interferometer reference and object illumination beams. A complementary metal-oxide semiconductor camera, incorporating a digital signal processor, is used to carry out real-time signal processing of the interferometer output to allow multipoint LDV(More)
A laser Doppler vibrometer (LDV) is described which uses a CMOS digital camera, incorporating a digital signal processor, to carry out real-time signal processing of the interferometer output to allow multipoint LDV to be implemented. The synthetic-heterodyne technique is used to overcome the interferometric fading effect due to slow environmental changes.(More)
We present the development of a panchromatic acrylamide-based photopolymer (ABP) for holographic recording application. The scattering of the recording medium was characterized by measuring the bidirectional scattering distribution function. The dynamic range in the reflection mode of recording was evaluated by measuring the diffraction efficiencies of the(More)
Holographic recording in thick photopolymer layers is important for application in holographic data storage, volume holographic filters, and correlators. Here, we studied the characteristics of acrylamide-based photopolymer layers ranging in thickness from 250 microm to 1 mm. For each thickness, samples with three different values of absorbance were(More)
For optical data storage applications, it is essential to determine the lowest intensity (also known as threshold intensity) below or at which no data page or grating can be recorded in the photosensitive material, as this in turn determines the data capacity of the material. Here, experiments were carried out to determine the threshold intensity below(More)
We report a simple, compact electronic speckle-pattern interferometer (ESPI) incorporating holographic optical elements (HOEs) for the study of out-of-plane vibration. Reflection and transmission HOEs provide reference and object beams in the interferometer. The alignment difficulties with conventional ESPI systems are minimized using HOEs. The time-average(More)
An analyte or measurand may change the diffraction efficiency of a hologram or the colour of a reflection hologram. The formation of a holographic grating can itself be a sensing action. Holographic optical elements (HOEs) can provide the reference and object beams in an unbalanced, out-of-plane sensitive, electronic speckle pattern interferometer for(More)
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