A. P. Gavrilyuk

Effect of local environment in resonant domains of polydisperse plasmonic nanoparticle aggregates on optodynamic processes in pulsed laser fields

Interactions of pulsed laser radiation with resonance domains of multiparticle colloidal aggregates having an increasingly complex local environment are studied via an optodynamic model. The model is applied to the simplest configurations, such as single particles, dimers, and trimers consisting of mono- and polydisperse Ag nanoparticles. We analyze how the local environment and the associated local field enhancement by surrounding particles affect the optodynamic processes in domains, including their photomodification and optical properties.

Plasmonic Nanoparticle Aggregates in High-Intensity Laser Fields: Effect of Pulse Duration

We use an optodynamic model to study the interaction of pulsed laser radiation of different duration with mono- and polydisperse dimers and trimers of plasmonic nanoparticles as resonant domains of colloid Ag multiparticle aggregates. A comparative analysis of the influence of pulse duration on the kinetic characteristics of domains accompanied by the change in their local structure was carried out taking into account the intensity of incident radiation. The obtained results explain the reasons for laser photochromic reactions in materials containing colloidal aggregates of plasmonic nanoparticles.

Restructuring of plasmonic nanoparticle aggregates with arbitrary particle size distribution in pulsed laser fields

We have studied processes of interaction of pulsed laser radiation with resonant groups of plasmonic nanoparticles (resonant domains) in large colloidal nanoparticle aggregates having different interparticle gaps and particle size distributions. These processes are responsible for the origin of nonlinear optical effects and photochromic reactions in multiparticle aggregates. To describe photo-induced transformations in resonant domains and alterations in their absorption spectra remaining after the pulse action, we introduce the factor of spectral photomodification. Based on calculation of changes in thermodynamic, mechanical, and optical characteristics of the domains, the histograms of the spectrum photomodification factor have been obtained for various interparticle gaps, an average particle size, and the degree of polydispersity. Variations in spectra have been analyzed depending on the intensity of laser radiation and various combinations of size characteristics of domains. The obtained results can be used to predict manifestation of photochromic effects in composite materials containing different plasmonic nanoparticle aggregates in pulsed laser fields.

Thermal effects in systems of colloidal plasmonic nanoparticles in high-intensity pulsed laser fields [Invited]: publisher’s note

Thermal effects in systems of colloidal plasmonic nanoparticles in high-intensity pulsed laser fields [Invited] : publishers note (vol 7,pg 555, 2017)

The Role of the Electron Tunneling Effect in the Coagulation Kinetics of Polydisperse Metal Nanocolloids

The energy of pair interactions between metal nanoparticles of different sizes is shown to be able to increase upon coagulation due to the additional electrostatic effect resulting from mutual heteropolar charging of the particles. The tunnel electron transfer occurring upon the collisions between particles of different sizes may be the reason for the charging. The transfer is caused by the dependence of the electron work function on the particle size. The electron transfer through the interparticle gap equalizes the Fermi levels in particles of different sizes and is associated with this dependence. Using the example of bimodal silver nanocolloids, it is shown that mutual heteropolar charging of particles with different sizes may accelerate the coagulation of polydisperse colloidal systems by an order of magnitude or more as compared with monodisperse systems, in which this effect is absent.

Evolution of extinction spectra of monolayer plasmon-resonant colloidal crystals in the process of their synthesis by the moving meniscus method

Regularities of the evolution of the extinction spectra of periodic colloidal structure composed of silver nanoparticles formed from bulk hydrosol on the surface of dielectric substrate are studied using the moving meniscus method. Spectra were calculated by the coupled dipole method. The effect of individual parameters of disperse system on the pattern of extinction contour in the band of plasmon absorption of a synthesized two-dimensional crystalline structure is analyzed.

RESONANCE LASER ACTIONS AS AN EFFICIENT METHOD FOR CONTROL OF THE GAS AND PLASMA STATES

The results obtained by the authors in studies of the mechanical action of resonance laser light on gas and plasma are briefly reviewed.

Effects of the interaction between an optical membrane and plasma

A model is considered for the interaction with plasma of an “optical membrane” formed by bichromatic intersecting laser beams. This model is used to describe a number of effects resulting from the mechanical action of light on resonant ions in the plasma.

Laser cooling and Wigner crystallization of rarefied plasma

For the first time the optical method of electron-ion plasma cooling, trapping and crystallizing (on microscale) due to laser radiation action on plasma with resonant ions is proposed.

Selective optical trap for low-temperature plasma

The possibility is demonstrated of utilizing resonant light pressure to provide prolonged selective optical confinement of a low-temperature plasma with resonant ions. For this purpose it is proposed to employ rectified gradient forces in strong interfering bichromatic fields and laser cooling methods.