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A new “Extinction model” was developed to calculate aggregation threshold. The possibility of creating a forecasting model is shown on the example of establishing a correlation between aggregation and NLO properties.

This work is devoted to studying the aggregation effect on the nonlinear optical (NLO) and charge transport (CT) properties of low-symmetry phthalocyanines bearing a cyclotriphosphazene moiety, a monomer, and clamshell-type bis-phthalocyanine. FE-SEM and AFM studies revealed ordered nanoaggregation in these compounds, represented as repeating objects of regular configuration, globules (340–480 nm), which contain small aggregates inside their cavity, similar to smoothed polygons (ca. 40 nm). Such specificity is not characteristic of other functionalized phthalocyanines, which we dealt with earlier. A new spectral method for estimating the aggregation threshold based on the change in extinction with increasing concentration of solutions was also implemented, and the effect of aggregation on optical limiting was demonstrated. The behavior of isomers and rotamers of bis-phthalocyanine in the presence of electric fields of various strengths was investigated with the DFT calculations, and that partially corresponds to the impact of laser radiation on molecules. It was shown that the unusual behavior of the trans-isomer in FF-DFT calculations is the reason for the worsening of the NLO and CT characteristics of bis-phthalocyanine, in which the macrocycles are strapped through a phosphazene spacer. An advanced method of multiparametric analysis has been implemented to evaluate the NLO and CT properties of the dyes in general.

Laser-power-limiting devices play a predominant role in photonics because of their potential for protecting human eyes and optical devices that are sensitive to intense laser beams. This paper describes a new methodology for predicting the efficiency of optical limiting based on electric-field-induced changes in absorption spectra calculated with the TDDFT quantum-chemical method. Analytical equations are derived to evaluate the optical thresholds and speed of switching on, the dynamic range, and the degree of nonlinear attenuation of the radiation fluxes for the case of two-photon absorption. Thus, the researcher does not need to conduct costly experiments to evaluate the suitability of nonlinear absorbers for the creation of optical limiters. The possibility of developing a forecasting model is demonstrated by an example of a series of stable slipped-cofacial phthalocyanine J-type dimers, which were synthesized and investigated previously.

The effect of ultrashort laser radiation parameters on the process of biomaterial formation based on dispersed media of bovine serum albumin and carbon nanotubes was studied. It is noted that, in contrast to the use of continuous laser radiation of comparable power, the composite nanomaterial is formed when lower temperatures are reached, which provides additional advantages and a smaller change in the protein structure. This effect can also be associated with a pulse repetition rate of 80 MHz, in the interval, which is about 12.5 ns, partial cooling of the material can occur, while this effect is sufficient for the formation of a biomaterial. The hardness of this material is comparable to that of native tissue. A strong twofold change in the elasticity of such a material in comparison with drying in air indicates the formation of an inner framework of carbon nanotubes. The possibility of this effect is also confirmed by spectral studies, according to which, at the used wavelength of 810 nm, the radiation is absorbed mainly by carbon nanotubes and only as a result of heat transfer is transmitted to bovine serum albumin and is spent on water evaporation. In vitro studies of cell growth in the presence of biomaterial were carried out by quantitative (MTT test) and qualitative (microscopy) methods. It was found that the number of cells grown on the composites exceeds the number of cells in the control after 72 hours of incubation. The cells on the composites formed a monolayer, their morphology does not differ from the morphology of the cells in the control. In vitro studies indicate a positive effect of the biomaterial on cell adhesion and proliferation and, consequently, on the possibility of their use for tissue regeneration.

The widespread application of laser devices requires development of new protections against light pulses of high intensity. This problem is relevant because of the danger of hitting the civil aviation pilots with bright and powerful radiation originating from the laser sources which are widely used in the everyday life. Therefore, this work is devoted to continuing our research on a new class of macroheterocyclic compounds – thermally and chemically stable J-type phthalocyanine dimers as potential nonlinear absorbers for optical limiting technology. The dimeric complexes of magnesium (1a) and zinc (1b) were covalently bonded to single-walled carbon nanotubes (SWCNTs) to improve the overall characteristics of the potential optical limiters 2a,b as compared to the previously studied corresponding dyes in solutions. The conjugates obtained were investigated using atomic force microscopy (AFM), as well as Raman and IR spectroscopy to confirm formation of the covalent binding of phthalocyanine macrocycles with the carbon surface. Open-aperture Z-scan and a fixed limiter location experiments have demonstrated low values of the limiting threshold and high degree of attenuation of the input laser radiation with the pulses duration located in the nanosecond range.

The technology of structuring arrays of multilayer carbon nanotubes using pulsed laser radiation is presented. Arrays of two types nanotubes (long and short) with different morphologies were synthesized on a silicon substrate by the method of plasma enhanced chemical vapor deposition from the gas phase. Samples with arrays of nanotubes located strictly perpendicular to the silicon substrate were obtained using an ytterbium fiber laser (1064 nm) with a galvanometric scanner. Raman spectroscopy showed a decrease in the defectiveness of the carbon nanostructure of the tubes after laser irradiation. Liquid treatment with Ba(NO3)2 applied to the array with subsequent annealing resulted in sticking of the nanotubes at their tips. The formation of cellular structure from array of carbon nanotubes with a greater length after laser scanning of the sample was observed. Such arrays of nanotubes made it possible to increase the current of electron emission by more than two times at lower threshold voltage compared with the original arrays of nanotubes. The current density increased from 65 to 150 μA/cm2. Structured arrays of nanotubes can be used to create efficient emission cathodes, as well as sensors, solar cells and MEMS structures.

The structural parameters and vibrational IR and Raman spectra of the molecular unit of the chitosan polymer, chitosan dimer, and chitosan dimer in complex with SWCN fragment were calculated. It is shown that the interaction of the chitosan dimer with SWCNTs leads to a change in the valence angle of the COS linking the elementary units of the chitosan biopolymer and the valence angle of the hydrogen bond bridge C ... .NO. In the IR spectra, an increase in the intensity of the absorption bands in the region of ~1000 cm-1 is observed, and in the Raman spectra – an increase in the intensity of the lines in the low-frequency region of ~400-600 cm-1.

In this paper, we studied the effect of long-term pulsed laser radiation from visible range on an aqueous dispersion with single-walled carbon nanotubes with a concentration of 0.005%. The dependence of the normalized transmission on time, the temperature dependence, and nonlinear optical characteristics were determined. In several minutes of irradiation, bubbles appeared in the dispersion and enlightenment was observed, i.e. increase in transmission. It was determined that an aqueous dispersion with carbon nanotubes retains its optical characteristics for 600 pulses at a laser pulses frequency of 10 Hz and power of 230 mW.

It has been established that carbon nanotubes and their aggregates can be arranged in the form of a linear chain under the action of laser radiation in an aqueous dispersion of a biological composite nanomaterial.

Aqueous dispersed media and films based on edible or succinate chitosan with single-walled carbon nanotubes (SWCNTs) were manufactured. Infrared spectroscopy and Raman spectroscopy were used to study the structural changes associated with formation of intermolecular junctions between chitosan and SWCNT. Nonlinear optical characteristics of liquid samples exposed to pulsed laser radiation of nanosecond duration were determined experimentally and calculated theoretically. The composition of the medium based on succinate chitosan and SWCNT providing the largest nonlinear absorption coefficient (902 cm/GW) was determined. The sample with this composition had lower threshold radiation intensity (2.7 MW/cm2), at which nonlinear effects are generated in the medium and liquid-to-solid transition occurs. The results obtained in this work are useful for laser-based production of three-dimensional cellular and tissue-engineered structures used in cardiovascular surgery.

The ability to form sutures in bovine tendon using a prototype laser biological tissue welding device was demonstrated. New solder compositions are proposed, based on carbon nanotubules (0.1% w/w) in an aqueous matrix of bovine serum albumin (25% w/w) supplemented with the medical laser dye indocyanine green (0.01% w/w). The absorption peak of the nanocomposition solder coincided with the apparatus wavelength of 800 nm. The use of indocyanine green as radiation absorber in nanocomposition solders provided increases in the strength of laser weld sutures in tendons. The maximum level of ~0.82 MPa was achieved using a solder based on multiwalled carbon nanotubules. X-Ray microtomography demonstrated uniformity in the joining of tendons in depth and length during formation of nanocomposite between the two welded biological tissue fragments. Growth of fibroblast cells on the composite surface formed at the site of the laser weld suture was demonstrated.

Biopolymer composites based on two types of chitosan (chitosan succinate and low-molecular weight chitosan) with single-walled carbon nanotubes (SWCNT) were created by laser printing. SWCNT have good dispersibility in chitosan solutions and therefore, can form relatively homogeneous films that was shown in scanning electron microscopy images. For the studies film composites were formed under the action of laser radiation on aqueous dispersion media. Study of the nonlinear optical process during the interaction of laser radiation with a disperse media has shown that low-molecular chitosan has a large nonlinear absorption coefficient of 17 cm/GW, while the addition of SWCNT lead to a significant increase up to 902 cm/GW. The threshold intensity for these samples was 5.5 MW/cm2 with nanotubes. If intensity exceeds the threshold value, nonlinear effects occur, which, in turn, lead to the transformation of a liquid into a solid phase. Characterization of films by FTIR and Raman spectroscopy indicated arising molecular interactions between chitosan and SWCNT detected as a small frequency shift and a change in the shape of radial breathing mode (RBM). The results indicate the possibility using aqueous dispersion media based on chitosan and SWCNT to create three-dimensional films and scaffolds for tissue engineering by laser printing.

In this paper, we investigated the effects of near-infrared (1.06 µm) pulsed laser radiation on aqueous dispersions of bovine serum albumin (BSA) and bovine collagen (BC) with single-walled carbon nanotubes (SWCNTs), which can be used as inks for printing biocompatible three-dimensional cellular and tissue engineered structures. Determination of linear and nonlinear optical characteristics was performed using optical spectroscopy and fixed sample location method. Protein dispersions without carbon nanotubes practically did not exhibit nonlinear properties, while the same dispersions with SWCNTs showed strong absorption of optical radiation with incident beam energy increase. This confirms that the nonlinear absorption coefficient in presence of nanotubes is 2-3 orders greater than without nanotubes depending on the threshold intensity values. This suggests that the laser formation of three-dimensional structures had no optical effect on proteins, and denaturation basically occurred due to the heat transfer from carbon nanotubes, which absorbed most of the laser radiation.

The study of nonlinear optical effects in the interaction of femtosecond laser radiation with a water dispersion of collagen and single-walled carbon nanotubes was carried out. Studies were conducted in the wavelength range of 715-890 nm. The technique with a fixed sample location is used to determine nonlinear optical effects. Collagen was used in studies with different concentrations. At wavelengths of 715 nm and 790 nm, nonlinear absorption was detected. When exposed to samples by laser radiation with a wavelength of 890 nm, the effect of nonlinear clearing was observed, which was associated with the departure of nanoparticles under the influence of heat from the irradiation zone. Irradiation of dispersions at a wavelength of 840 nm did not reveal nonlinear optical effects. Thus, it was found that these dispersions can be used as nonlinear optical limiters as well as biocompatible inks for 3D bioprinting.

This paper examines the formation of a structure with micro- or nano-sizes on the surface of a biocompatible nanocomposite under the influence of high-power laser pulses. The main components of a biocompatible nanocomposite are bovine serum albumin and carbon nanotubes. A laser installation was used to obtain structures on the surface of the experimental samples, the main element of which is the femtosecond titanium-sapphire laser (pulse duration – 140 fs, pulse frequency – 80 MHz). Besides, the installation includes power attenuator, mechanical shutter (exposure duration - 5 ms), focusing lens with a 10 cm focal distance and moving platform for samples. The nanocomposite surface was irradiated with laser pulses with different powers in the range of 150-300 mW. After the treatment the samples’ surface has been studied with electronic microscope to get more details. Was discovered structure of elevations and depressions with microraster covered with a fibrous structure.

Based on a comprehensive theoretical and experimental approach, a low-defect thin film of stable dimeric phthalocyanine zinc complex (bis-[2-hydroxy-9(10),16(17), 23(24)-tri-tert-butylphthalocyanine]zinc – J-[OHPctZn]2) was prepared. It is shown that the dye forms stable amorphous edge-on monolayers at the air/water interface with an insignificant content of cylindrical 3D aggregates. These floating layers keep their structure when transferred by the Langmuir-Schaefer method onto a solid substrate, demonstrating a tendency towards ordered H-aggregation with preserving their linear molecular properties. Mixed two- and three-photon absorption of femtosecond laser pulses (280 fs) was firstly detected on this sample, as well as the ability of a material to the nonlinear attenuation of the intense irradiation, which is important for optical limiting.

A laser technology has been developed for fabricating structures from composite layers based on biopolymers: albumin, collagen, and chitosan with single-walled carbon nanotubes (SWCNT). The structures are intended for cardiovascular devices and tissue-engineered implants. This is evidenced by the results of studies. The composite layers were fabricated due to the phase transition of biopolymers and SWCNT aqueous dispersion under the influence of laser pulses. At the same time branched 3D networks of SWCNT were formed in the biopolymer matrix. The threshold energy fluence of laser pulses was determined (0.032–0.083 J/cm2) at which a bimodal distribution of pores was observed. The calculation of contact resistances between nanotubes at percolation units of 3D networks (20–100 kOhm) was carried out. Composite layers fabricated by laser demonstrated conductivity values that were higher (12.4 S/m) than those for layers by thermostat (4.7 S/m). The maximum hardness of the composite layers with SWCNT (0.01 wt%) by laser was 482 ± 10, 425 ± 10, and 407 ± 15 MPa for albumin, collagen and chitosan, respectively. The hardness of the thermostat layers was less than 100 MPa. The viability of endothelial cells in composite layers was improved. The composite layers ensured a normal level of hemolysis during interaction with erythrocytes.

Laser radiation makes it possible to form a composite material with laser radiation, which is intended for use as cellular- and tissue-engineering structures. It is important to obtain a uniform distribution of components throughout the volume of such material. Intermolecular interactions between chitosan and single-walled carbon nanotubes (SWCNTs) affect the structure of the composite. The results of IR spectroscopy and nonlinear optical studies have shown that the effect of laser radiation has different effects on the two types of chitosan, which was clearly demonstrated by SEM studies. Upon detailed examination, agglomerates in the composite material are clearly visible. Chitosan succinate less prevents the formation of agglomerates from SWCNTs, as a result of which a high agglomeration of nanotubes occurs among themselves in the composite material. The corresponding formations are distinguishable in the SEM images.

Low limiting thresholds have been demonstrated on thermally stable phthalocyanine J-type dimeric complexes of Mg and Zn. The effective “threshold” model based on radiative transfer phenomena in nonlinear optical (NLO) media was suggested for exact definition of the nonlinear absorption coefficient and the optical limiting threshold.

A device for laser welding of biological tissues was developed. The main elements of the device are a laser guidance system and an adaptive thermal stabilization system. The laser solder is based on a water−albumin dispersion of single-layer carbon nanotubes (SCNTs). The properties of the SCNTs were tested using scanning electron microscopy. The surface of the weld was found to have cracks up to 10 μm in width and 150 μm in length. The cracks contained SCNT bundles

The possibility of developing new advanced optical limiters of laser radiation at 532 nm with low limiting thresholds has been demonstrated on thermally stable phthalocyanine J-type dimeric complexes of Mg, Zn, Cu, Ni, and Co. A new "threshold" model based on radiative transfer phenomena in nonlinear optical media was suggested for the exact definition of nonlinear absorption coefficient β and optical limiting threshold Ic. This model allows the determination of the optical characteristics of the limiter in the same active material with layers of different thicknesses, as well as the use of different parameters of laser radiation, such as cross-sectional spatial profiles of the laser beam and shapes of the laser pulse over time. The maximum value of the nonlinear absorption coefficient (β = 360 cm GW(-1)) and the lowest limiting threshold (Ic = 0.03 J cm(-2)) were estimated for a J-type zinc phthalocyanine dimer.

We studied the formation of a composite from an aqueous dispersed medium with albumin and carbon nanotubes under the action of laser radiation in continuous wave (CW) mode and pulsed mode with a repetition rate of 10 Hz and pulse duration of 16 ns. During the experiments, the temperature was monitored at the site of exposure, as well as its distribution in the liquid. Pulsed solid-state Nd:YAG laser and CW diode laser with an irradiation power of ∼500 mW were used as radiation sources. However, a three-dimensional composite was formed only with constant exposure. The effect of pulsed laser radiation with an intensity corresponding to nonlinear interaction with water dispersion led only to its enlightenment. Thus, it is important not only the energy parameters of radiation but also the frequency of energy portions exposure for the fabrication of tissue-engineered structures (composites). As a result, it was found that the curing of the dispersion and the composite formation occurs under the action of continuous or pulsed (with a high pulse repetition rate) laser radiation at a temperature in the range from 45°C to 50°C; in case the pulse repetition rate is insufficient, composite formation is not observed even under the action of high intensity radiation and heating occurs only to a temperature of ∼40 ° C. This formation process can be generated both in the visible 532 nm and in the infrared 810-nm wavelength ranges. In this case, one of the main conditions is the absence of albumin or cells absorption at these wavelengths so that absorption occurs mainly with single-walled carbon nanotubes. Studies of the surface and internal structure of the composite made it possible to demonstrate the binding of nanotubes to each other. This happened under the influence of laser radiation. This led to high hardness values of the composites. The average value of hardness was 0.26 ± 0.02 GPa.

This paper presents a study of structures based on chitosan and single-walled carbon nanotubes (SWCNT) carried out by vibrational spectroscopy methods (IR and Raman). Volumetric structures were created by the layer-by-layer laser evaporation of aqueous dispersion. The nature of the intermolecular bonds between nanotubes and chitosan has been clarified. These structures can be used for the cellular- and tissue engineering of the cardiovascular system.

Optical absorbers can be used to attenuate laser radiation to a safe level. At the same time, it is necessary to ensure high transmission of nonhazardous low-intensity radiation and a sharply reduced transmission at high intensity. To achieve this basic requirement can be due to nonlinear optical effects. In addition, the developed absorbers can be added to the formation of three-dimensional tissue-engineered structures. Thus, it will be possible to control the thickness of the layer being formed.

This article presents the studies results for nonlinear optical characteristics of protein aqueous dispersions (bovine serum albumin and bovine collagen) with single-walled carbon nanotubes (SWCNTs). These characteristics were obtained using Z-scan experiments and fixed sample location experiments with a fixed position of the sample. Calculations were made using a method based on the radiation transfer equation.

The technology of cell 3D scaffolds laser fabrication is developed. 3D scaffolds are designed to repair osteochondral defects, which are poorly restored during the organism’s life. The technology involves the use of an installation, the laser beam of which moves along a liquid nanomaterial and evaporates it layer by layer. Liquid nanomaterial consists of the water-protein (collagen, albumin) suspension with carbon nanoparticles (single-walled carbon nanotubes). During laser irradiation, the temperature in the region of nanotubes defects increases and nanotubes are combined into the scaffold. The main component of installation is a continuous laser operating at wavelengh of 810 nm. The laser beam moves along 3 coordinates, which makes it possible to obtain samples of the required geometric shape. The internal and surface structure of the samples at the micro- and nanoscale levels were studied using the X-ray microtomography and scanning electron microscopy. In vitro studies of cell growth during 48 and 72 hours demonstrated the ability of cell 3D scaffolds to support the proliferation of osteoblasts and chondroblasts. Using fluorescence and atomic force microscopy, it was found that the growth and development of cells on a sample with a larger concentration of nanotubes occurred faster compared to samples with a smaller concentration of nanotubes.

Laser radiation limiters can be made on the basis of working substances, which have strong nonlinear effects after reaching a certain critical value (threshold limiting). Thus, it becomes possible to obtain a high transmission for a safe beam and a sharply reduced transmission for a hazardous beam. To determine the nonlinear and linear optical properties of these materials there were carried out comprehensive spectroscopic studies, experiments by Z-scan methods with an open aperture and a fixed location of the limiter. Working substances was developed which is suspension of conjugates J-type phthalocyanine dimers Zn or Mg with single-walled carbon nanotubes (SWCNTs) in water. Created conjugates can be used not only for protecting eyes and light-sensitivity elements, but for forming three-dimensional tissueengineered structures. Using conjugates J-type phthalocyanine dimers Zn and Mg with SWCNTs will increase the optical absorption in the wavelength range of laser processing by reducing the thermal effect on other substances in the composition of this structure. The Nd:YAG laser was used as the laser radiation source for generating pulses of 16 ns duration at a wavelength of 532 nm with the linearly polarized laser beam in the horizontal plane and a shape of Gaussian type. The threshold of limiting, linear and nonlinear absorption coefficients were determined by output characteristic, that was obtained by fixed location of the limiter. Created working substances have values of the following order: linear absorption coefficient ~ 3 cm-1 for layer of 0.2 cm thickness, low limiting threshold ~ 1 MW·cm-2 and high value of the nonlinear absorption coefficient ~ 550 cm GW-1 . Knowing the nonlinear optical parameters, Z-scan data with an open aperture can be calculated for comparison with experimental data.

To print three-dimensional cellular- and tissue-engineered structures intended for implantation in the damaged area of cardiovascular system, it is necessary to know the nonlinear optical characteristics of using materials. Therefore, studies of the effect of pulsed nanosecond laser radiation on proteins such as bovine serum albumin (BSA), bovine collagen (BC), and single-walled carbon nanotubes (SWCNTs) were carried out. Experiments were carried out with the open-aperture z-scan method and fixed sample location method. Z-scan curve and input-output energy curve were obtained. Four samples of aqueous dispersions were used: 25 % BSA with water, 2 % BC with water and the same samples with SWCNTs. The linear transmission of the samples were determined by optical spectroscopy method. The limiting threshold, linear and nonlinear absorption coefficients were calculated for each dispersion. It was found that absorption of albumin and collagen dispersions with SWCNT increased sharply with the increase of the input radiation fluency.

The results of experimental creation of nanocomposites using femtosecond laser are presented. We have theoretically proved the formation of a carbon nanotube frame in a protein matrix during laser structuring of single-walled carbon nanotubes. We have selected the technological parameters of synthesis of nanocomposites, which provide the proliferation of living cells.

In this work, we studied the structural changes of bovine serum albumin (BSA) that occur due to its denaturation caused by the thermal heating of the protein dispersion. The characteristic Raman spectroscopy peaks indicate the BSA conformation. Specifically, 1578 cm−1 corresponds to the native conformation, and 1608 cm−1 and 1660 cm−1 correspond to the denatured state.

Composite biomaterial consists of bovine serum albumin 25 wt. % and single-walled carbon nanotubes

In this paper, we have studied the crystallization behavior of amorphous GST225 thin films upon irradiation with nanosecond laser pulses. Crystalline and melt-quenched amorphous regions were produced by exposure to laser single or multipulses, and were characterized by the optical microscopy and by the micro-Raman spectroscopy. Transition region between the amorphous and crystalline parts of the laser-modified area was investigated by atomic force microscopy. Using irradiation by single laser pulses with varying fluence, it was verified that crystallization was possible if the fluence is more than 90.4 mJ/cm2.

The effect of nanosecond pulses of laser radiation of different energy on the oriented CNT array synthesized by catalytic plasma-induced deposition from a gas phase on a silicon substrate was studied. It is shown that the following effects are possible: CNT ablation, the effect of CNT alignment (straightening), singling, and "splicing" of individual CNTs in a single structure, as well as changing the morphology of the array itself. Structuring of CNTs at a given area using impulse nanosecond radiation moving using a galvanometric scanner system is obtained. Nanotubes are less defective after laser modification. This is proved by Raman spectroscopy. This treatment can be used for electron emission devices, CNT-based detectors and topological elements.

Determination of nonlinear optical characteristics of active substances of the limiters of high-power laser radiation was carried out with the help of non-threshold and new threshold models. Experimental data of z-scan with open aperture was obtained, which helped to determine values of the nonlinear optical characteristics for dispersion media with carbon nanotubes and graphene oxide. Advantages of threshold model experimental data processing in comparison with non-threshold model was shown.

Creation of effective means of protection from laser radiation of high power requires the development of optical materials (working substance), with their transparence being decreased sharply above a certain critical value of the laser intensity due to the appearance of non-linear optical properties (limiting threshold). Based on the threshold model, the working substance of the optical limiter was characterized. Experimental data of z-scan with open aperture are used to determine the nonlinear optical parameters of solutions of dimeric phthalocyanine complexes of Mg and Zn of J-type in tetrahydrofuran (THF) and thin films of their conjugates with single-walled carbon nanotubes (SWCNTs). The output characteristic (output (peak) fluence vs input (peak) fluence), that describes the basic properties of optical limiters, was obtained with the fixed location of the optical limiter. Dimeric phthalocyanine complexes were found to have low limiting threshold ~ 2 MW·cm-2 and high value of the nonlinear absorption coefficient ~ 330 and 370 cm GW-1, respectively. Conjugates of these dimeric phthalocyanines with SWCNTs have been produced for the improving of the limiting parameters and increasing of the optical nonlinearity. Size of J-type dimeric phthalocyanine complexes of Mg and Zn were determined by the scanning electron microscopy (SEM). The atomic force microscopy (AFM) allowed to determine the dimensions of nanotubes. The structure parameters, such as diameter and defects as well as the strength of aggregates were estimated with the Raman spectroscopy. For our experiments, the lens with a focal length of 20 cm was used. As the laser radiation source, the Nd:YAG laser was used to generate pulses of 16 ns duration at a wavelength of 532 nm with the linearly polarized laser beam in the horizontal plane and a shape closed to Gaussian type. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

3-D bioconstructions were created using the evaporation method of the water-albumin solution with carbon nanotubes (CNTs) by the continuous and pulsed femtosecond laser radiation. It is determined that the volume structure of the samples created by the femtosecond radiation has more cavities than the one created by the continuous radiation. The average diameter for multi-walled carbon nanotubes (MWCNTs) samples was almost two times higher (35-40 nm) than for single-walled carbon nanotubes (SWCNTs) samples (20-30 nm). The most homogenous 3-D bioconstruction was formed from MWCNTs by the continuous laser radiation. The hardness of such samples totaled up to 370 MPa at the nanoscale. High strength properties and the resistance of the 3-D bioconstructions produced by the laser irradiation depend on the volume nanotubes scaffold forming inside them. The scaffold was formed by the electric field of the directed laser irradiation. The covalent bond energy between the nanotube carbon molecule and the oxygen of the bovine serum albumin aminoacid residue amounts 580 kJ/mol. The 3-D bioconstructions based on MWCNTs and SWCNTs becomes overgrown with the cells (fibroblasts) over the course of 72 hours. The samples based on the both types of CNTs are not toxic for the cells and don't change its normal composition and structure. Thus the 3-D bioconstructions that are nanostructured by the pulsed and continuous laser radiation can be applied as implant materials for the recovery of the connecting tissues of the living body.

Laser welding device for biological tissue has been developed. The main device parts are the radiation system and adaptive thermal stabilization system of welding area. Adaptive thermal stabilization system provided the relation between the laser radiation intensity and the weld temperature. Using atomic force microscopy the structure of composite which is formed by the radiation of laser solder based on aqua- albuminous dispersion of multi-walled carbon nanotubes was investigated. AFM topograms nanocomposite solder are mainly defined by the presence of pores in the samples. In generally, the surface structure of composite is influenced by the time, laser radiation power and MWCNT concentration. Average size of backbone nanoelements not exceeded 500 nm. Bulk density of nanoelements was in the range 10 6 -10 8 sm -3 . The data of welding temperature maintained during the laser welding process and the corresponding tensile strength values were obtained. Maximum tensile strength of the suture was reached in the range 50-55°C. This temperature and the pointwise laser welding technology (point area ~ 2.5mm) allows avoiding thermal necrosis of healthy section of biological tissue and provided reliable bonding construction of weld join. In despite of the fact that tensile strength values of the samples are in the range of 15% in comparison with unbroken strips of pigskin leather. This situation corresponds to the initial stage of the dissected tissue connection with a view to further increasing of the joint strength of tissues with the recovery of tissue structure; thereby achieved ratio is enough for a medical practice in certain cases.

Dispersive and composite nanomaterials based on multi-walled and single-walled carbon nanotubes and its conjugates with dye of zinc phthalocyanine were produced. The composition and the structure of dispersive and composite materials were investigated using analytical methods of spectroscopy and microscopy. Nonlinear characteristic of nanomaterials of limiters by direct nonlinear scanning and Z-scan method were investigated. Studies suggest the possibility of using such nanomaterials in laser intensity limiters. Proposed threshold model characterizing limiters of powerful laser radiation takes into account the threshold nature of nonlinear interaction of irradiation with the nonlinear material. Threshold effect of nonlinear interaction of laser irradiation with several nonlinear material based on multi-walled and single-walled carbon nanotubes was experimentally found. It was shown that threshold model fit better with experimental data of Z-scan.