Rajasree, K; Ravikumar, A V; Radhakrishnan, P; Nampoori, V P N; Vallabhan, C P G(Springer, April , 1992)
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Abstract:
Photothermal deflection technique was used for determining the laser damage threshold of polymer samples of teflon (PTFE) and nylon. The experiment was conducted using a Q-switched Nd-YAG laser operating at its fundamental wavelength (1-06μm, pulse width 10 nS FWHM) as irradiation source and a He-Ne laser as the probe beam, along with a position sensitive detector. The damage threshold values determined by photothermal deflection method were in good agreement with those determined by other methods.
Thomas, Baby; Nampoori, V P N(Solid State Communications, 1992)
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Abstract:
A method of preparation of strontium sulphide phosphors doped
with europium is given. Nitrogen laser excited fluorescence emission
spectra of these phosphors in the visible region are recorded. A band
with line structure in the region 350-430 nm and a new broad band at
460 nm are observed. The splitting pattern for the 6p levels of Eu 2+ are
given.
Radhakrishnan, P; Nampoori, V P N; Vallabhan, C P G(Indian Journal of Physics, 1992)
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Abstract:
A simple fiber optic concentration sensor based on the coupling of light f rom one
fiber to another through a solution is discussed. The operational characteristics of the sensor are
illustrated by taking the solutions of potassium permanganate and fast green dye as samples.The extrinsic type sensor described here shows linearity at lower concentrations.