Dynamics of glass-forming liquids. XX. Third harmonic experiments of non-linear dielectric effects versus a phenomenological model

AbstractThe excited state properties of dyes become important under intense illumination of a short laser pulse. The pulse induces a significant population in an excited state which will have different absorptive properties, this causes a change in absorption of the incident pulse within its duration. An increase in absorption arises from molecules in an excited state having an absorption greater than the corresponding ground state.The z-scan technique has been used to measure the induced absorption of a carbocyanine dye 1,1′,3,3,3′,3′- Hexamethylindtricarbocyanine Iodide (HITCI) for laser pulses of different wavelengths. An optical parametric oscillator pumped by the third harmonic of a Q-switched Nd:YAG laser was used. Z-scans were taken at a number of different wavelengths between 460 and 630 nm. Data is presented which shows the spectral region where induced absorption occurs. An eight level rate equation model is used to predict the non-linear behaviour and to fit to the experimental data, good correlation is found between the model and data.

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Non-linear increase and saturation of third-harmonic yield from supported silver nanostructures excited by IR femtosecond laser pulses

Laser Physics Letters ◽

10.1088/1612-2011/13/3/035302 ◽

2016 ◽

Vol 13 (3) ◽

pp. 035302 ◽

Cited By ~ 5

Author(s):

Stanislav G Bezhanov ◽

Pavel N Danilov ◽

Andrey A Ionin ◽

Sergey I Kudryashov ◽

Vasiliy N Lednev ◽

...

Keyword(s):

Femtosecond Laser ◽

Laser Pulses ◽

Femtosecond Laser Pulses ◽

Linear Increase ◽

Silver Nanostructures ◽

Third Harmonic ◽

Non Linear

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DYNAMICAL NON-LINEAR SUSCEPTIBILITY OF THE QUENCHED AND ANNEALED FRUSTRATED LATTICE GAS MODELS

Fractals ◽

10.1142/s0218348x03001768 ◽

2003 ◽

Vol 11 (supp01) ◽

pp. 99-107 ◽

Cited By ~ 1

Author(s):

ANTONIO DE CANDIA ◽

ANNALISA FIERRO ◽

ANTONIO CONIGLIO

Keyword(s):

Characteristic Time ◽

Lattice Gas ◽

Glass Forming ◽

Dynamical Susceptibility ◽

First Case ◽

Non Linear ◽

Lattice Gas Models ◽

Kinetic Constraint ◽

Analogous Behavior ◽

Frustrated Lattice

In this paper we study the 3D frustrated lattice gas model in the quenched and annealed versions. In the first case, the dynamical non-linear susceptibility grows monotonically as a function of time, until reaching a plateau that corresponds to the static value. The static non-linear susceptibility diverges at some density, signaling the presence of a thermodynamical transition. In the annealed version, where the disorder is allowed to evolve in time with a suitable kinetic constraint, the thermodynamics of the model is trivial, and the static non-linear susceptibility does not show any singularity. Nevertheless, the model shows a maximum in the dynamical non-linear susceptibility at a characteristic value of the time. Approaching the density corresponding to the singularity of the quenched model, both the maximum and the characteristic time diverge. We conclude that the critical behavior of the dynamical susceptibility in the annealed model is related to the divergence of the static susceptibility in the quenched case. This suggests a similar mechanism also in supercooled glass-forming liquids, where an analogous behavior in the dynamical non-linear susceptibility is observed.

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