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Your search keyword '"Venkatramaiah, N."' showing total 2 results
Start Over Author "Venkatramaiah, N." Publisher american institute of physics
2 results on '"Venkatramaiah, N."'

1. Nonlinear optical properties of graphene- (OH, Sn) porphyrin composites in picosecond regime.

Author

Krishna, M. Bala Murali, Venkatramaiah, N., Venkatesan, R., and Rao, D. Narayana

Subjects
*NONLINEAR optics, *GRAPHENE, *PORPHYRINS spectra, *PICOSECOND pulses, *TWO-photon absorbing materials, *OPTICAL switching, *COMPOSITE materials
Abstract

The nonlinear optical (NLO) properties of covalently linked Graphene-(Sn, OH) porphyrin composite materials were investigated using Z-scan technique at 532 nm with picosecond laser pulses. We have observed enhanced figure of merit values for composites in comparison with individual graphene, copper and zinc porphyrin. The enhanced figure of merit values for graphene-porphyrin composite material should be attributed to two-photon absorption and excited state absorption. We also observed different behavior, reverse saturable absorption to saturable absorption and back to reverse saturable absorption in composite molecules leading to better ultrafast nonlinear optical switching applications. [ABSTRACT FROM AUTHOR]

Published
2011
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2. Nonlinear optical properties of covalently linked graphene-metal porphyrin composite materials.

Author

Krishna, M. Bala Murali, Kumar, V. Praveen, Venkatramaiah, N., Venkatesan, R., and Rao, D. Narayana

Subjects
NONLINEAR optics, GRAPHENE, PORPHYRINS, METALLIC composites, OPTICAL measurements, COMPARATIVE studies, SCATTERING (Physics), EXCITED state chemistry
Abstract

The nonlinear optical (NLO) and optical limiting (OL) properties of covalently linked graphene-porphyrin composite materials were investigated using Z-scan technique in nanosecond regime. We observed enhanced NLO and OL properties of graphene-porphyrin composites in comparison to the individual graphene and porphyrins. The improved OL property of composites is attributed to energy transfer between porphyrin and graphene, which improved excited state absorption and nonlinear scattering. Nonlinear optical susceptibilities χ(3) of graphene and graphene-porphyrin composites were, in the order of 10-12 esu, measured using degenerate four wave mixing technique in nanosecond regime. High values of excited state absorption and two-photon absorption were observed for the composites. [ABSTRACT FROM AUTHOR]

Published
2011
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