Nampoori, V P N; Litty, Irimpan; Bindu, Krishnan; Radhakrishnan, P(Elsevier Journal of Colloid and Interface Science, April 29, 2008)
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Abstract:
In this article we present the spectral and nonlinear optical properties of ZnO–TiO2 nanocomposites prepared
by colloidal chemical synthesis. Emission peaks of ZnO–TiO2 nanocomposites change from 340 nm
to 385 nm almost in proportion to changes in Eg. The nanocomposites show self-defocusing nonlinearity
and good nonlinear absorption behaviour. The nonlinear refractive index and the nonlinear absorption
increase with increasing TiO2 volume fraction at 532 nm and can be attributed to the enhancement of
exciton oscillator strength. ZnO–TiO2 is a potential nanocomposite material for the tunable light emission
and for the development of nonlinear optical devices with a relatively small limiting threshold
Litty, Irimpan; Bindu, Krishnan; Nampoori, V P N; Radhakrishnan, P(Elsevier, 2008)
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Abstract:
In this article we present the nonlinear optical properties of ZnO–TiO2–SiO2 nanocomposites prepared by colloidal chemical synthesis. Nonlinear optical response of these samples is studied using nanosecond laser pulses at an off-resonance wavelength. The nonlinearity of the silica colloid is low and its nonlinear response can be improved by making composites with ZnO and TiO2. These nanocomposites show self-defocusing nonlinearity and good nonlinear absorption behaviour. The nonlinear refractive index and the nonlinear absorption increases with increasing ZnO volume fraction. The observed nonlinear absorption is explained by two photon absorption followed by weak free carrier absorption and nonlinear scattering. ZnO–TiO2–SiO2 is a potential nanocomposite material for the development of nonlinear optical devices with a relatively small limiting threshold.