Title:	Ultrafast optical power limiting in free-standing Pt - polyvinyl alcohol nanocomposite films synthesized in situ
Authors:	Karthikeyan, B. Anija, M. Venkatesan, P. Suchand Sandeep, C.S. Philip, Reji
Issue Date:	Dec-2007
Publisher:	Elsevier B.V.
Citation:	Optics Communications, 2007, Vol.280, p482-486
Abstract:	Free-standing platinum–polyvinyl alcohol nanocomposite films have been prepared by a simple in situ method. By thermal annealing, Pt nanoparticles of different sizes and shapes have been obtained. Their optical nonlinearity is measured using ultrafast (100 fs) laser pulses at 404 nm, in the absorption wing region. A strong optical power limiting is found in the films. The timescale of this limiting action is ultrafast, as it happens within the incident laser pulsewidth. Experimental results and numerical simulation indicate that the sign of the nonlinearity can be controlled by varying the film composition and annealing temperature. Use of ultrashort laser pulses in the free-standing film configuration permits a direct and unambiguous determination of the electronic nonlinearity of the material, since accumulative effects occur at later times lying outside the sharp measurement window.
Description:	Restricted Access.
URI:	http://hdl.handle.net/2289/3447
ISSN:	ISSN: 0030-4018
Alternative Location:	http://dx.doi.org/10.1016/j.optcom.2007.08.046
Copyright:	2007 Elsevier
Appears in Collections:	Research Papers (LAMP)

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