Cheranellore Sudha Kartha

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We report the observation of a self-written waveguide inside a bulk methylene blue sensitized poly/vinyl alcohol)/acrylamide photopolymer material. Light from a low power He-Ne laser is focused into the material, and the evolution of the beam is monitored. The refractive index of the material is modulated in the region of high intensity due to(More)
A methylene-blue-sensitized polymer blend of polyvinyl alcohol and polyacrylic acid is fabricated and tested for holographic recording. It was found to have good characteristics such as high sensitivity, storage stability, ease of fabrication, and environmental stability. Optimization of the ratio of polyvinyl alcohol/polyacrylic acid, the sensitizer(More)
An investigation on the panchromaticity of a silver-doped poly(vinyl alcohol)/acrylamide photopolymer system is presented in this paper. Frequency-doubled Nd:YAG (532 nm) and Ar⁺ (488 nm) lasers were used for the characterization of the films. Previous studies using an He-Ne laser (632.8 nm) showed that plane-wave transmission grating with a high(More)
Incorporation of silver ions into a dye-sensitized poly(vinyl alcohol)/acrylamide photopolymer is observed to give better performance compared to other metal-ion-doped photopolymer holographic recording media. Plane-wave transmission gratings were recorded in the photopolymer films using a He-Ne laser, and various holographic parameters were optimized so as(More)
The nonlinear optical molecule N,N-bis(4-bromobutyl)-4-nitrobenzenamine was synthesized. The ground state dipole moment was determined by the Debye-Guggenheim method. A solvent mixture of acetonitrile and toluene was used for the solvatochromic determination of the excited state dipole moment. Excited state has a high value for the dipole moment which(More)
The diffraction efficiency, sensitivity, and storage life of methylene blue-sensitized poly(vinyl chloride) film was improved by the addition of an electron donor in the matrix. The addition of pyridine enhanced the diffraction efficiency by two times, and storage life of the gratings was increased to 2-3 days.
A new polymer matrix sensitized with methylene blue for use as an optical recording material is described here. The characterization is done to determine the optimal recording conditions. These films need no chemical development and are found to be stable for several months. The matrix has excellent shelf life and needs an exposure only as short as 20 s.(More)
An indigenously developed chemical spray pyrolysis system was used to deposit polycrystalline CuInS2 thin films. It was found that smaller spray rate results in films with better crystallinity and lower resistivity. Increase in surface roughness of the films was observed for higher spray rates. Variations in film stoichiometry with composition of spray(More)
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