Nazariy Andrushchak - Academia.edu (original) (raw)

Papers by Nazariy Andrushchak

2018 IEEE 8th International Conference Nanomaterials: Application & Properties (NAP)

In this paper, the technology of growing ammonium dihydrogen phosphate (ADP) crystals in pores of... more In this paper, the technology of growing ammonium dihydrogen phosphate (ADP) crystals in pores of nanoporous aluminum oxide (Al2O3) matrices was presented. On the grown nanocomposites, the optical properties of such structures were studied. In particular, the direct and diffuse optical transmission, as well as specular reflection of Al2O3 matrices with ADP crystals grown in nanopores, were analyzed. From the performed experimental studies, it can be concluded that the transmission and scattering of pure Al2O3 porous matrices and with ADP crystals in nanopores depends largely on the properties of the Al2O3 matrices and the technology of their production.

2020 IEEE 15th International Conference on Advanced Trends in Radioelectronics, Telecommunications and Computer Engineering (TCSET)

We report the synthesis, structure and nonlinear optical properties of cadmium sulphide (CdS) nan... more We report the synthesis, structure and nonlinear optical properties of cadmium sulphide (CdS) nanocrystallines (NCs) synthesized electrochemically both with and without detergent ATLAS G3300. Relevant structural and morphological features are explored by X-ray diffraction and scanning electron microscopy (SEM) techniques. The efficiency of the second harmonic generation (SHG) appears to be strongly dependent on the energy density of the incident fundamental laser radiation and NC sizes.

2021 IEEE 16th International Conference on the Experience of Designing and Application of CAD Systems (CADSM)

In this paper, we have discussed a new approach for measuring the dielectric permittivity of crys... more In this paper, we have discussed a new approach for measuring the dielectric permittivity of crystalline and nanocomposite materials at subTHz frequency range. The proposed approach's idea is based on the interferometric method, where the shifts in the interference fringes are received by introducing the wedge from the epoxy risen in one arm of the interferometer. All the measuring processes are controlled by means of the LabVIEW programming language. The proposed method was experimentally verified on the Fused Silica and BK-7 glasses. The received values of dielectric permittivity are in good agreement with the one from the literature.

2020 IEEE 15th International Conference on Advanced Trends in Radioelectronics, Telecommunications and Computer Engineering (TCSET)

In this paper, we have obtained the ratio for the diffraction efficiency of the interaction of te... more In this paper, we have obtained the ratio for the diffraction efficiency of the interaction of terahertz electromagnetic radiation and the acoustic wave, taking into account the absorption of both acoustic and electromagnetic waves. It also took into account the reflection of electromagnetic waves at the input and output surfaces of the lightsoundwire. Furthermore, requirements have been formed both for materials that can be used for the development of acousto-optic devices which can operate in the terahertz frequency range. We have evaluated the magnitude of the acousto-optic performance of devices based on oxide single crystals, which can operate in the sub-Terahertz frequency range.

Journal of Alloys and Compounds

Combining dielectric crystals with mesoporous solids allows a versatile design of functional nano... more Combining dielectric crystals with mesoporous solids allows a versatile design of functional nanomaterials, where the porous host provides a mechanical rigid scaffold structure and the molecular filling adds the functionalization. Here, we report a study of the complex lattice dynamics of a SiO2:KH2PO4 nanocomposite consisting of a monolithic, mesoporous silica glass host with KH2PO4 nanocrystals embedded in its tubular channels ∼12 nm across. A micro-Raman investigation performed in the spectral range of 70-1600 cm −1 reveals the complex lattice dynamics of the confined crystals. Their Raman spectrum resembles the one taken from bulk KH2PO4 crystals and thus, along with X-ray diffraction experiments, corroborates the successful solution-based synthesis of KH2PO4 nanocrystals with a structure analogous to the bulk material. We succeeded in observing not only the high-frequency internal modes (∼900-1200 cm −1), typical of internal vibrations of the PO4 tetrahedra, but, more importantly, also the lowest frequency modes typical of bulk KH2PO4 crystals. The experimental Raman spectrum was interpreted with a group theory analysis and firstprinciple lattice dynamics calculations. The calculated phonon spectrum reveals a lattice instability against two optical modes probably related to an intrinsic anharmonicity of the vibrational dynamics of KH2PO4 crystals originating from the uncertainty of proton localization within the network of hydrogen bonds. The analysis of calculated eigen-vectors indicates the involvement of hydrogen atoms in most phonon modes corroborating the substantial significance of the hydrogen subsystem in the lattice dynamics of paraelectric bulk and of KH2PO4 crystals in extreme spatial confinement. A marginal redistribution of relative Raman intensities of the confined compared to unconfined crystals presumably originates in slightly changed crystal fields and interatomic interactions, in particular for the parts of the nanocrystals in close proximity to the silica pore surfaces.

2017 IEEE 7th International Conference Nanomaterials: Application & Properties (NAP), 2017

KDP/Al 2 O 3 crystalline nanocomposite was obtained by growth of KDP nanocrystals from saturated ... more KDP/Al 2 O 3 crystalline nanocomposite was obtained by growth of KDP nanocrystals from saturated aqueous solution inside nanopores of amorphous alumina matrix Al 2 O 3 . The analysis of crystalline structure and surface morphology performed by XRD and AFM showed that Al 2 O 3 matrix is filled up with KDP nanocrystals of tetragonal phase in preferred crystallographic orientation (200). The nonlinear optical (NLO) response was studied by means of second harmonic generation (SHG) via Maker fringe technique using picosecond laser pulses at wavelength of 1064 nm. The obtained dependence of SHG intensity on laser polarization was explained by the anisotropy of macroscopic crystalline structure of KDP/Al 2 O 3 nanocomposite.

2018 14th International Conference on Advanced Trends in Radioelecrtronics, Telecommunications and Computer Engineering (TCSET), 2018

A principal possibility of formation the nanostructures on the surfaces of 50PbO-25Bi2O3-20Ga2O3-... more A principal possibility of formation the nanostructures on the surfaces of 50PbO-25Bi2O3-20Ga2O3-5BaO (doped by Eu 3+ , Er 3+ , Dy 3+) is demonstrated by using multicoherent beams. As a sources of the photoinducing coherent light we have used nanosecond Nd:YAG and Er:Yb lasers generating at 1064 nm and 1540 nm, respectively. The morphology of the photoinduced surfaces is sensitive to the type of rare earth ions. The thickness of the layer was about 20…30 nm. Possible mechanisms are explained by coherent photoinduction of the valence electrons.

2017 14th International Conference The Experience of Designing and Application of CAD Systems in Microelectronics (CADSM), 2017

The detection and elimination principle of redundant elements in the mathematical model is descri... more The detection and elimination principle of redundant elements in the mathematical model is described. This principle has been used for the reduction of various mathematical models of dynamical systems in the form of systems of differential equations and artificial neural networks. In a simplified form, this principle is applied to the reduction model of optimal vector for global maximum of induced optical effect in crystalline materials. On the example of linear electro-optic effect in lithium niobate crystals we have found the optical coefficients that are fully or partially do not affect the resulting global maximum for investigated indicative surfaces.

Acta Physica Polonica A, 2018

Study of Second Harmonic Generation in KDP/Al2O3 Crystalline Nanocomposite N. Andrushchak, B. Kul... more Study of Second Harmonic Generation in KDP/Al2O3 Crystalline Nanocomposite N. Andrushchak, B. Kulyk, P. Göring, A. Andrushchak and B. Sahraoui Lviv National Polytechnic University, 12 S. Bandery Str., 79013 Lviv, Ukraine Research and Educational Center Fractal , Department of Physics, Ivan Franko National University of Lviv, 50 Dragomanova Str., 79005 Lviv, Ukraine SmartMembranes GmbH, Heinrich-Damerow-Str. 4, 06120 Halle, Germany University of Angers, MOLTECH-Anjou Laboratory, UMR CNRS 6200, 2 bd Lavoisier, 49045 Angers, France

2019 IEEE 15th International Conference on the Experience of Designing and Application of CAD Systems (CADSM), 2019

In the paper, it is proposed a new approach to designing a 3D scanning device taking into account... more In the paper, it is proposed a new approach to designing a 3D scanning device taking into account the technical specification and the existing base of available components for further assembly. Based on the designed model, using the SolidWorks development software a 3D model of the 3D scanning device was produced. Furthermore, the key elements and possible structures and models were presented in details. To run the scanner, the software was developed and algorithms of transferring received data from camera view to real-world coordinates were developed using Python. The approbation of its operation was performed on the test object of the specific dimensions and the experimental results show the correctness of the proposed methods and developed mechanisms for object scanning.

2017 14th International Conference The Experience of Designing and Application of CAD Systems in Microelectronics (CADSM), 2017

In this paper a new approach for image processing technique of different resolutions and size was... more In this paper a new approach for image processing technique of different resolutions and size was developed. The method was implemented on specially built experimental setup and utilizing the Python software with its special libraries such as scikit-image. The developed method was tested on series of images of different resolutions (640×480, 1280×720, 1920×1080, 2592×1944). The results of its implementation can be easily adapted in other systems, such as 3D scanners, where identification of certain objects is needed and processing time maters.

Nanoscale, 2021

A liquid crystal-infused nanoporous solid acts as a photonic metamaterial with thermo-electricall... more A liquid crystal-infused nanoporous solid acts as a photonic metamaterial with thermo-electrically tunable static and dynamic birefringence.

2021 IEEE 11th International Conference Nanomaterials: Applications & Properties (NAP), 2021

In this paper, the modified technology of nanoporous aluminum oxide (Al2O3) matrices filling with... more In this paper, the modified technology of nanoporous aluminum oxide (Al2O3) matrices filling with the KDP, ADP, and TGS crystals is proposed. The transmission spectra of the grown structures were studied at 300 -3000 nm and 50-1200 GHz spectral ranges. Because of the performed investigation, due to the significant transmission of nanoporous matrices in the terahertz range, in-depth analysis needs to be performed for their use as substrates for the implementation of nanoplasmonic devices, given the regular (periodic) structure of nanopores in these matrices.

2018 14th International Conference on Advanced Trends in Radioelecrtronics, Telecommunications and Computer Engineering (TCSET), 2018

In this paper the state-of-the-art for exploiting the unique physical and chemical properties of ... more In this paper the state-of-the-art for exploiting the unique physical and chemical properties of crystalline materials and their possible applications for development of crystalline nanocomposites with the tailored anisotropy were discussed. Using a method of growing crystals from a solution the KDP and TGS nanocrystalites were grown in the mezopores of the Al2O3 matrix. To investigate the developed nanocrystalline samples the X-ray analysis was used. A form of the obtained diffractograms and our calculations show the predominant crystallization of the KDP and TGS in the direction [100], which coincides with the direction of the cylindrical pores. Thus, diffractograms contain only reflexes of crystallographic planes (200) and (400). The achieved result indicates the possibility of growing of nanocrystals in mesopores of such Al2O3 structures developed by us and provides the prospect of creating optical cells with increased energy efficiency.

Optical Materials, 2021

Abstract The optimal geometries of vector phase matching are determined for the cases of second h... more Abstract The optimal geometries of vector phase matching are determined for the cases of second harmonic, sum and difference frequency generation in often-used uniaxial nonlinear optical crystals – KDP, ZnGePe2, GaSe, LiIO3, LiNbO3, BBO. The directions of wave vectors ensuring the highest possible efficiency of generation are defined by the extreme surfaces method. As it is shown, in a significant number of cases, the vector phase matching ensures higher efficiencies than the scalar one.

SLAS TECHNOLOGY: Translating Life Sciences Innovation, 2019

In the paper, we explain an automated LabVIEW-controlled setup that enables interferometric measu... more In the paper, we explain an automated LabVIEW-controlled setup that enables interferometric measurement of refractive indices in crystalline materials using a laser light source. The setup combines a mechanical system, a microcomputer-controlled gearless drive, a Michelson interferometer, an optical detector, a data acquisition system, and a LabVIEW virtual instrument for an accurate nondestructive determination of the refractive index of given plane-parallel samples. We explain the concept, implementation, and hardware/software peculiarities of the developed system. Test experiments on different crystals yielded results that are in good agreement with available reference data. The range of potential applications of the proposed setup extends from fundamental optical research to biophotonics instrumentation, where efficient delivery of light is of crucial importance and reliable automated probing tools are needed for optical component characterization.

Optical Materials, 2020

In the present study, Mg-doped ZnO (MZO) nanofilms (NF) were grown by spray pyrolysis technique. ... more In the present study, Mg-doped ZnO (MZO) nanofilms (NF) were grown by spray pyrolysis technique. X-ray diffraction (XRD) patterns have shown an intense peak oriented along (002) crystalline plane confirming crystalline origin of grown MZO films. Atomic force microscopy (AFM) data revealed that the average roughness decreased significantly upon Mg doping from 20.3 nm to 4.72 nm. Ambient temperature photoluminescence spectra accounted for four emission bands in the visible spectral region due to the presence of various intrinsic defect centres in the films. The non-linear absorption coef eff) were estimated by open aperture Z-scan technique and found to be in the order of 10-2 (cm/W) and indicates a positive absorption nonlinearity. Additionally, it was observed that incorporation of the metal Mg ions leads to a decay of the second harmonic generation (SHG) and to a non-regular increase of the third harmonic generation (THG).

Acta Physica Polonica A, 2018

The numerical method of the effective refractive index of porous composite materials calculation ... more The numerical method of the effective refractive index of porous composite materials calculation was improved by implementation of microlevel cellular structural models. The proposed solution gives the ability uniformly to analyse complex structural inhomogeneities and to synthesize the corresponding index based on the simulation of electrostatic field. The proposed realization is simpler and takes less computations capacities in comparison to analogous simulation methods. The method was probed on the example of SiO2 nanoporous matrix with refractive index n = 1.426 at λ = 2.71 µm wavelength. The results of simulation are in good agreement with other analytical models from literature.

2018 IEEE 8th International Conference Nanomaterials: Application & Properties (NAP)

In this paper, the technology of growing ammonium dihydrogen phosphate (ADP) crystals in pores of... more In this paper, the technology of growing ammonium dihydrogen phosphate (ADP) crystals in pores of nanoporous aluminum oxide (Al2O3) matrices was presented. On the grown nanocomposites, the optical properties of such structures were studied. In particular, the direct and diffuse optical transmission, as well as specular reflection of Al2O3 matrices with ADP crystals grown in nanopores, were analyzed. From the performed experimental studies, it can be concluded that the transmission and scattering of pure Al2O3 porous matrices and with ADP crystals in nanopores depends largely on the properties of the Al2O3 matrices and the technology of their production.

2020 IEEE 15th International Conference on Advanced Trends in Radioelectronics, Telecommunications and Computer Engineering (TCSET)

We report the synthesis, structure and nonlinear optical properties of cadmium sulphide (CdS) nan... more We report the synthesis, structure and nonlinear optical properties of cadmium sulphide (CdS) nanocrystallines (NCs) synthesized electrochemically both with and without detergent ATLAS G3300. Relevant structural and morphological features are explored by X-ray diffraction and scanning electron microscopy (SEM) techniques. The efficiency of the second harmonic generation (SHG) appears to be strongly dependent on the energy density of the incident fundamental laser radiation and NC sizes.

2021 IEEE 16th International Conference on the Experience of Designing and Application of CAD Systems (CADSM)

In this paper, we have discussed a new approach for measuring the dielectric permittivity of crys... more In this paper, we have discussed a new approach for measuring the dielectric permittivity of crystalline and nanocomposite materials at subTHz frequency range. The proposed approach's idea is based on the interferometric method, where the shifts in the interference fringes are received by introducing the wedge from the epoxy risen in one arm of the interferometer. All the measuring processes are controlled by means of the LabVIEW programming language. The proposed method was experimentally verified on the Fused Silica and BK-7 glasses. The received values of dielectric permittivity are in good agreement with the one from the literature.

2020 IEEE 15th International Conference on Advanced Trends in Radioelectronics, Telecommunications and Computer Engineering (TCSET)

In this paper, we have obtained the ratio for the diffraction efficiency of the interaction of te... more In this paper, we have obtained the ratio for the diffraction efficiency of the interaction of terahertz electromagnetic radiation and the acoustic wave, taking into account the absorption of both acoustic and electromagnetic waves. It also took into account the reflection of electromagnetic waves at the input and output surfaces of the lightsoundwire. Furthermore, requirements have been formed both for materials that can be used for the development of acousto-optic devices which can operate in the terahertz frequency range. We have evaluated the magnitude of the acousto-optic performance of devices based on oxide single crystals, which can operate in the sub-Terahertz frequency range.

Journal of Alloys and Compounds

Combining dielectric crystals with mesoporous solids allows a versatile design of functional nano... more Combining dielectric crystals with mesoporous solids allows a versatile design of functional nanomaterials, where the porous host provides a mechanical rigid scaffold structure and the molecular filling adds the functionalization. Here, we report a study of the complex lattice dynamics of a SiO2:KH2PO4 nanocomposite consisting of a monolithic, mesoporous silica glass host with KH2PO4 nanocrystals embedded in its tubular channels ∼12 nm across. A micro-Raman investigation performed in the spectral range of 70-1600 cm −1 reveals the complex lattice dynamics of the confined crystals. Their Raman spectrum resembles the one taken from bulk KH2PO4 crystals and thus, along with X-ray diffraction experiments, corroborates the successful solution-based synthesis of KH2PO4 nanocrystals with a structure analogous to the bulk material. We succeeded in observing not only the high-frequency internal modes (∼900-1200 cm −1), typical of internal vibrations of the PO4 tetrahedra, but, more importantly, also the lowest frequency modes typical of bulk KH2PO4 crystals. The experimental Raman spectrum was interpreted with a group theory analysis and firstprinciple lattice dynamics calculations. The calculated phonon spectrum reveals a lattice instability against two optical modes probably related to an intrinsic anharmonicity of the vibrational dynamics of KH2PO4 crystals originating from the uncertainty of proton localization within the network of hydrogen bonds. The analysis of calculated eigen-vectors indicates the involvement of hydrogen atoms in most phonon modes corroborating the substantial significance of the hydrogen subsystem in the lattice dynamics of paraelectric bulk and of KH2PO4 crystals in extreme spatial confinement. A marginal redistribution of relative Raman intensities of the confined compared to unconfined crystals presumably originates in slightly changed crystal fields and interatomic interactions, in particular for the parts of the nanocrystals in close proximity to the silica pore surfaces.

2017 IEEE 7th International Conference Nanomaterials: Application & Properties (NAP), 2017

KDP/Al 2 O 3 crystalline nanocomposite was obtained by growth of KDP nanocrystals from saturated ... more KDP/Al 2 O 3 crystalline nanocomposite was obtained by growth of KDP nanocrystals from saturated aqueous solution inside nanopores of amorphous alumina matrix Al 2 O 3 . The analysis of crystalline structure and surface morphology performed by XRD and AFM showed that Al 2 O 3 matrix is filled up with KDP nanocrystals of tetragonal phase in preferred crystallographic orientation (200). The nonlinear optical (NLO) response was studied by means of second harmonic generation (SHG) via Maker fringe technique using picosecond laser pulses at wavelength of 1064 nm. The obtained dependence of SHG intensity on laser polarization was explained by the anisotropy of macroscopic crystalline structure of KDP/Al 2 O 3 nanocomposite.

2018 14th International Conference on Advanced Trends in Radioelecrtronics, Telecommunications and Computer Engineering (TCSET), 2018

A principal possibility of formation the nanostructures on the surfaces of 50PbO-25Bi2O3-20Ga2O3-... more A principal possibility of formation the nanostructures on the surfaces of 50PbO-25Bi2O3-20Ga2O3-5BaO (doped by Eu 3+ , Er 3+ , Dy 3+) is demonstrated by using multicoherent beams. As a sources of the photoinducing coherent light we have used nanosecond Nd:YAG and Er:Yb lasers generating at 1064 nm and 1540 nm, respectively. The morphology of the photoinduced surfaces is sensitive to the type of rare earth ions. The thickness of the layer was about 20…30 nm. Possible mechanisms are explained by coherent photoinduction of the valence electrons.

2017 14th International Conference The Experience of Designing and Application of CAD Systems in Microelectronics (CADSM), 2017

The detection and elimination principle of redundant elements in the mathematical model is descri... more The detection and elimination principle of redundant elements in the mathematical model is described. This principle has been used for the reduction of various mathematical models of dynamical systems in the form of systems of differential equations and artificial neural networks. In a simplified form, this principle is applied to the reduction model of optimal vector for global maximum of induced optical effect in crystalline materials. On the example of linear electro-optic effect in lithium niobate crystals we have found the optical coefficients that are fully or partially do not affect the resulting global maximum for investigated indicative surfaces.

Acta Physica Polonica A, 2018

Study of Second Harmonic Generation in KDP/Al2O3 Crystalline Nanocomposite N. Andrushchak, B. Kul... more Study of Second Harmonic Generation in KDP/Al2O3 Crystalline Nanocomposite N. Andrushchak, B. Kulyk, P. Göring, A. Andrushchak and B. Sahraoui Lviv National Polytechnic University, 12 S. Bandery Str., 79013 Lviv, Ukraine Research and Educational Center Fractal , Department of Physics, Ivan Franko National University of Lviv, 50 Dragomanova Str., 79005 Lviv, Ukraine SmartMembranes GmbH, Heinrich-Damerow-Str. 4, 06120 Halle, Germany University of Angers, MOLTECH-Anjou Laboratory, UMR CNRS 6200, 2 bd Lavoisier, 49045 Angers, France

2019 IEEE 15th International Conference on the Experience of Designing and Application of CAD Systems (CADSM), 2019

In the paper, it is proposed a new approach to designing a 3D scanning device taking into account... more In the paper, it is proposed a new approach to designing a 3D scanning device taking into account the technical specification and the existing base of available components for further assembly. Based on the designed model, using the SolidWorks development software a 3D model of the 3D scanning device was produced. Furthermore, the key elements and possible structures and models were presented in details. To run the scanner, the software was developed and algorithms of transferring received data from camera view to real-world coordinates were developed using Python. The approbation of its operation was performed on the test object of the specific dimensions and the experimental results show the correctness of the proposed methods and developed mechanisms for object scanning.

2017 14th International Conference The Experience of Designing and Application of CAD Systems in Microelectronics (CADSM), 2017

In this paper a new approach for image processing technique of different resolutions and size was... more In this paper a new approach for image processing technique of different resolutions and size was developed. The method was implemented on specially built experimental setup and utilizing the Python software with its special libraries such as scikit-image. The developed method was tested on series of images of different resolutions (640×480, 1280×720, 1920×1080, 2592×1944). The results of its implementation can be easily adapted in other systems, such as 3D scanners, where identification of certain objects is needed and processing time maters.

Nanoscale, 2021

A liquid crystal-infused nanoporous solid acts as a photonic metamaterial with thermo-electricall... more A liquid crystal-infused nanoporous solid acts as a photonic metamaterial with thermo-electrically tunable static and dynamic birefringence.

2021 IEEE 11th International Conference Nanomaterials: Applications & Properties (NAP), 2021

In this paper, the modified technology of nanoporous aluminum oxide (Al2O3) matrices filling with... more In this paper, the modified technology of nanoporous aluminum oxide (Al2O3) matrices filling with the KDP, ADP, and TGS crystals is proposed. The transmission spectra of the grown structures were studied at 300 -3000 nm and 50-1200 GHz spectral ranges. Because of the performed investigation, due to the significant transmission of nanoporous matrices in the terahertz range, in-depth analysis needs to be performed for their use as substrates for the implementation of nanoplasmonic devices, given the regular (periodic) structure of nanopores in these matrices.

2018 14th International Conference on Advanced Trends in Radioelecrtronics, Telecommunications and Computer Engineering (TCSET), 2018

In this paper the state-of-the-art for exploiting the unique physical and chemical properties of ... more In this paper the state-of-the-art for exploiting the unique physical and chemical properties of crystalline materials and their possible applications for development of crystalline nanocomposites with the tailored anisotropy were discussed. Using a method of growing crystals from a solution the KDP and TGS nanocrystalites were grown in the mezopores of the Al2O3 matrix. To investigate the developed nanocrystalline samples the X-ray analysis was used. A form of the obtained diffractograms and our calculations show the predominant crystallization of the KDP and TGS in the direction [100], which coincides with the direction of the cylindrical pores. Thus, diffractograms contain only reflexes of crystallographic planes (200) and (400). The achieved result indicates the possibility of growing of nanocrystals in mesopores of such Al2O3 structures developed by us and provides the prospect of creating optical cells with increased energy efficiency.

Optical Materials, 2021

Abstract The optimal geometries of vector phase matching are determined for the cases of second h... more Abstract The optimal geometries of vector phase matching are determined for the cases of second harmonic, sum and difference frequency generation in often-used uniaxial nonlinear optical crystals – KDP, ZnGePe2, GaSe, LiIO3, LiNbO3, BBO. The directions of wave vectors ensuring the highest possible efficiency of generation are defined by the extreme surfaces method. As it is shown, in a significant number of cases, the vector phase matching ensures higher efficiencies than the scalar one.

SLAS TECHNOLOGY: Translating Life Sciences Innovation, 2019

In the paper, we explain an automated LabVIEW-controlled setup that enables interferometric measu... more In the paper, we explain an automated LabVIEW-controlled setup that enables interferometric measurement of refractive indices in crystalline materials using a laser light source. The setup combines a mechanical system, a microcomputer-controlled gearless drive, a Michelson interferometer, an optical detector, a data acquisition system, and a LabVIEW virtual instrument for an accurate nondestructive determination of the refractive index of given plane-parallel samples. We explain the concept, implementation, and hardware/software peculiarities of the developed system. Test experiments on different crystals yielded results that are in good agreement with available reference data. The range of potential applications of the proposed setup extends from fundamental optical research to biophotonics instrumentation, where efficient delivery of light is of crucial importance and reliable automated probing tools are needed for optical component characterization.

Optical Materials, 2020

In the present study, Mg-doped ZnO (MZO) nanofilms (NF) were grown by spray pyrolysis technique. ... more In the present study, Mg-doped ZnO (MZO) nanofilms (NF) were grown by spray pyrolysis technique. X-ray diffraction (XRD) patterns have shown an intense peak oriented along (002) crystalline plane confirming crystalline origin of grown MZO films. Atomic force microscopy (AFM) data revealed that the average roughness decreased significantly upon Mg doping from 20.3 nm to 4.72 nm. Ambient temperature photoluminescence spectra accounted for four emission bands in the visible spectral region due to the presence of various intrinsic defect centres in the films. The non-linear absorption coef eff) were estimated by open aperture Z-scan technique and found to be in the order of 10-2 (cm/W) and indicates a positive absorption nonlinearity. Additionally, it was observed that incorporation of the metal Mg ions leads to a decay of the second harmonic generation (SHG) and to a non-regular increase of the third harmonic generation (THG).

Acta Physica Polonica A, 2018

The numerical method of the effective refractive index of porous composite materials calculation ... more The numerical method of the effective refractive index of porous composite materials calculation was improved by implementation of microlevel cellular structural models. The proposed solution gives the ability uniformly to analyse complex structural inhomogeneities and to synthesize the corresponding index based on the simulation of electrostatic field. The proposed realization is simpler and takes less computations capacities in comparison to analogous simulation methods. The method was probed on the example of SiO2 nanoporous matrix with refractive index n = 1.426 at λ = 2.71 µm wavelength. The results of simulation are in good agreement with other analytical models from literature.