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The functional physical characteristics (electrophysical and optical properties) of a thin-film nanocluster system upon a change in the topology/morphology of surface solid structures are considered. Features of the fundamental physical effects in such systems allow us to talk about a new area of research: topological photonics, which has undoubted practical promise, particularly in the field of femtosecond nanoelectronics.

Functional physical properties of laser-induced nanocluster structures of different topology in the thin films deposited on solid surface and 3D-crystallic structures by femto-nanoexperiments are studied. Physical basis and specific topology nanocluster view are under our consideration with regard to the functional properties variation (electrophysics + optics) in granular structures. Modeling of electronic energy levels modification due to the topology factors and nonlinear dynamic model for coupled electronic states in the cluster system are carried out. New physical principles for possible application of such structures of topological photonics with different element compositions are discussed.

In the article we introduce the experiment of the photostimulation effect in the tunneling conductivity of free-standing thin carbyne-gold films. We observe a sharp increase of the conductivity of hybrid film due to the electromagnetic exciting at the frequencies which are close to the plasmon resonance of gold nanoparticles. The use of carbyne threads as a stabilizing matrix makes it possible to obtain free-standing thin films that demonstrate a good structural stability. The tunnel current–voltage measurements demonstrate a strong dependence of the current value on the intensity of green laser radiation used to photostimulate thin C–Au in area of the measuring experiment.

We consider experimentally and theoretically the detection of quantum states in nanocluster semiconductor/metal structures upon the registration of hopping/tunneling electrical conductivity and possible mechanisms of realization of such states. We obtain nanostructured thin films on the substrates using different technologies, including laser ablation of solid surfaces. We show that it is possible to control the properties of the films by varying the topology of such synthesized systems. We analyze the features arising due to the specific conductivity of granular media revealed by the measured current–voltage characteristics and electrical resistance dependences for nanocluster bimetallic films of different compositions.

Methods of laser modification allow us to observe macroscopic quantum phenomena in nanostructured (cluster) materials. The laser synthesis of nanoparticles/nanoclusters with different topologies in semiconductor PbTe samples is performed via direct laser modification of thin films under the action of continuous laser radiation with a wavelength of 1.06 μm and a power density of ~105 W/cm2. Nanoparticles with bimodal distribution in lateral dimensions are obtained on the surfaces of the samples. The electrophysical properties of such structures can be controlled as desired by modifying their topology. Variations in electric properties depending on the particle location density are demonstrated. The results are interpreted based on the existence of quantum coherent processes with tunneling transitions and hopping conductivity. This approach is promising for the fabrication of elements and devices in optoelectronics and photonics based on new physical principles, and of different hybrid optoelectrical schemes.

We applied a controlled method for producing nanostructures on glass substrates. We made detailed measurements to control the resulting micro-and nanostructures using as the principal example of surface modification of glassy carbon compositions under laser irradiation. The properties of the samples after laser irradiation were studied using atomic force microscopy (AFM) with an accuracy of about 10 nm in the scanning plane. The results of probing the material modification by the AFM images of its surface have been considered in frame of the nonlinear hydrodynamic mathematical approach and computer simulation.

Models of the formation of roughnesses on the surface of materials and the movement of distributed flows in their presence are considered, which ultimately determines the functional properties of such topological materials of different compositions induced by laser radiation. The paper also presents simulation of crystallization of complex structures from a melt with an analysis of the morphology of the resulting crystalline structures, and shows examples of the occurrence of fractal dendritic formations. Different types of morphology are induced depending on the energy of the laser radiation and the duration of the heating; determining the final state of objects with the desired functional and structural characteristics. Using the methods of cellular automata, the models were obtained for both the distribution of crystallization centers and the growth of an individual cluster under the influence of diffusion mechanisms. The relationship between the resulting morphology and the modified parameters of the models used is analyzed.

We experimentally realize nano-antennas based on hybrid silicon-gold nanoparticles (NPs). The silicon particles covered by clusters of small metal NPs are fabricated from a liquid phase under the effect of the laser irradiation. The complex nanoclusters containing both Si and Au components provide the enhancement of the near-field intensity and the resonant light scattering associated with excitation of multipole resonances in NPs. A strong sensitivity of the resonant light absorption to the hybrid particle size and material parameters is experimentally documented and theoretically discussed. The results demonstrate a high potentiality of the hybrid NPs for the realization of functional optical devices and metasurfaces.

The formation of hybrid silicon-gold NPs as a result of the laser action on a mixed colloidal solution is observed. These hybrid NPs are characterized by the amplification and broadening of the near-field photoluminescence spectra compared to pure silicon NPs. A strong sensitivity of the spectral shape of the emitted light to the intensity of the exciting white light is documented. These results may be used for the realization of functional metasurfaces consisting of randomly distributed resonant NPs. Moreover, as the synthesized NPs emit in red, green and yellow they can be used for fabrication of luminescent color screens.

We present the experimental and theoretical results of the study of laser modification of the solid phase of thin epitaxial films of lead telluride under continuous irradiation. An ensemble of nanoparticles with bimodal distribution depending on the laser power, beam diameter, and scanning rate of the surface is formed under laboratory conditions The process of the laser heating of a thin film is simulated, and the change in the temperature field, depending on the conditions of laser exposure, is described. The experimental results are interpreted based on the defect–deformation theory of the formation of a bimodal ensemble of nanoparticles under continuous laser irradiation. The diffusion model of cluster growth in the bulk and on the surface of a thin film demonstrates the possibility of forming a bimodal size distribution of clusters.

Tamm plasmons are confined optical states at the interface of a metal and a dielectric Bragg mirror. Unlike conventional surface plasmons, Tamm plasmons may be directly excited by an external light source in both TE and TM polarizations. Here we consider the one-dimensional propagation of Tamm plasmons under long and narrow metallic stripes deposited on top of a semiconductor Bragg mirror. The spatial confinement of the field imposed by the stripe and its impact on the structure and energy of Tamm modes are investigated. We show that the Tamm modes are coupled to surface plasmons arising at the stripe edges. These plasmons form an interference pattern close to the bottom surface of the stripe that involves modification of both the energy and loss rate for the Tamm mode. This phenomenon is pronounced only in the case of TE polarization of the Tamm mode. These findings pave the way to application of laterally confined Tamm plasmons in optical integrated circuits as well as to engineering potential traps for both Tamm modes and hybrid modes of Tamm plasmons and exciton polaritons with meV depth.

We have studied a solid-state laser modification of the surface of PbX semiconductor films under processes of self-organization for conditions when photon energies are above the band gap of the semiconductor. Experimental data were used to construct a model for defect deformation instability developing on the surface of epitaxial film through strain-induced drift of laser-induced point defects. The model is capable to describe qualitatively observed surface morphology and to predict the surface profile in laser modification experiments. It has been demonstrated that used approach is applied to analyze ant structure with various morphology which depends on parameters of laser action. By changing the electro-physical properties of the created structures in necessary direction we have a good opportunity to fabricate the new devices for optoelectronics and photonics of different kind.

This paper presents the results of experiments aimed at obtaining transparent carbon nanotube-nanofiber coatings by the laser irradiation of carbon targets in atmospheric air with a stream of ablated particles controlled by an external electric field and no metal catalyst.

The laser synthesis technique for producing nanoparticles/nanoclusters of different topology for semiconductor samples (PbTe) is presented by two laser ablation methods: direct laser modification of thin films and laser evaporation of substance from the target in liquid (ethanol) to produce a colloidal system, and the subsequent laser deposition of the particles from colloid on solid substrate [under continuous wave (cw)-laser, λ = 1.06 μm, laser intensity—up to 106 W/cm2]. Electro-physical properties of the induced structures have been controlled by various induced topology. It is obtained that electroresistance can dramatically decrease due to spontaneous selected multichannel/parallel electron transportation trajectories in the inhomogeneous cluster system. Two conditions are principal for that: the characteristic cluster size a

Laser processing of epitaxial PbSe films has been found to produce periodic concentric surface ring structures that extend over several laser spot radii from the exposed zone. The proposed theoretical interpretation of this effect in terms of defect — deformation interactions adequately describes the observed morphology, periodicity and complex (multimode) shape of the ring structures.

An experimental method is developed for preparing nanostructures in the field of high-power laser radiation (~107 W cm-2) upon deposition of vapours of carbon-containing materials on a cold substrate surface. A specific feature of the method is irradiation of a sample in air at room temperature and pressure close to 1 atm. The dependences of the morphologic properties of nanostructures on the distance between a substrate and a sample are determined. Variations in the size of deposited nanostructures and their characteristic shape depending on the chosen material are found.

The video image of the graphite surface exposed to focused laser radiation is obtained with the help of a laser monitor. A bright ring moving over the heated surface was observed. A method for reconstructing the surface relief from the video image is proposed and realised. The method is based on the measurement of the angular distribution of the light intensity scattered by the graphite sample surface. The surface relief of the graphite sample changing in time is reconstructed. The relative change in the relief height during laser excitation is measured. The statistical characteristics of the reconstructed graphite surface shape and their variation during laser irradiation are studied. It is found that a circular convexity appears within the bright ring. The formation mechanism of this convexity requires further investigations.

We report for the first time the formation of a nanoparticle ensemble on a binary semiconductor (PbTe) film under cw laser irradiation. It is shown that defect — deformation theory of the formation of nanoparticle ensembles in the solid state under cw laser irradiation adequately describes experimental data. In particular, it predicts a bimodal nanoparticle size distribution function that agrees well with the experimental distribution function.

Diagnostics of laser-induced instabilities on surface of substance has been carried out by means of fractal geometry and nonlinear dynamics methods. The spatial and temporal characteristics of optical images of melted metal surface were obtained. The obtained characteristics may be used for automatic control by laser technological processes. (Summary only available)

For the diagnostics of processes induced by laser radiation we developed the system on basis of copper laser. This system (laser monitor) consists of laser brightness amplifier, CCD-camera, computer, and allows to obtain the image of a processing surface through plasma plume in a real time. In contradistinction to classical schemes of laser processing our system realizes continuous visual control of processing surface directly in the process of laser radiation interaction with material. The computer analysis of obtained information allows to form control signals for the laser technological complex. The offered system provides the increasing of reliability and accuracy of carrying out measurements and can be used in various technological processes of treatment of metal. In this report we present the result of processing the optical images of dynamic processes on substance surface by fractal geometry methods.

We present the results of laser production of semiconductor nanoparticles under continuous laser action in the near-infrared range (up to 106?W?cm?2) on PbTe samples in air and liquid. We also present a method for forming nanoparticles on the surface of thin PbTe films and consider drop deposition for setting PbTe quantum dots on a substrate. Using a simulation model we describe the features of forming a deposited layer in the process of drop?evaporation.

The experimental studying of laser-induced hydrodynamic phenomena has been carried out by the system on base of laser brightness amplifier. The surface waves were registered and their parameters were determined. The form of free surface of melted by the laser radiation material was determined. New results of the field to study the laser- induced dynamic processes on the substance surface by the fractal geometry approach are presented.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.