6533b838fe1ef96bd12a3a84

RESEARCH PRODUCT

Nonlinear optical properties of silver nanoparticles: separating thermo-optical and Kerr effects

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In this paper, we present a study on thermo-optical effect in core-shell silver/thiol-termination ligand nanoparticles. Nanoparticles were dissolved in Dichloromethane. Experimental measurements were carried out using a Z-scan setup. As laser sources we used two 1064 nm lasers: i) 28 ps pulse width laser with 1000 Hz pulse repetition rate; ii) 8 ns pulse width laser with changeable pulse repetition rate 200 – 40 000 Hz. To study what processes lead to refractive index changes we used the polarization-resolved Z-scan method. Comparing ps and ns results showed that response time of single pulse thermal effects for organic solvents depends on beam size while for nanoparticles it corresponds to nanoparticle size. Measurements with ns laser using different lenses and pulse repetition rate showed that thermal response scales with the ratio of laser pulse repetition rate times beam size squared.