Phase grating patterning by direct laser recording on As2S3-Se nanomultilayers

Direct laser recording of surface relief gratings as phase holograms on successive evaporated As2S3 and Se nanomultilayers was studied in this paper. The surface relief gratings patterned on As2S3-Se nanomultilayers were investigated in dependence on polarization states of recording beams. It was shown that phase gratings are formed on the surface of the As2S3-Se nanomultilayers under the two linear polarized beams falling on the sample surface at (+45o)-(- 45o) relative to grating vector and the left-right circular polarizations. The influence of photo-induced mass transport on the surface relief formation process is discussed.The research was partly supported by the Project H2020-TWINN-2015 HOLO (687328)

Noise minimised high resolution digital holographic microscopy applied to surface topography

The topography of surface relief gratings was studied by digital holographic microscopy. The applicability of the method for quantitative measurements of surface microstructure at nanoscale was demonstrated. The method for wavefront reconstruction of surface relief from a digital hologram recorded in off-axis configuration was also applied. The main feature is noise filtration due to the presence of noise in the recorded intensity distribution and the use of all orders of the hologram. Reconstruction results proved a better effectiveness of our approach for topography studying of relief grating patterned on a ChG As2S3 – Se nanomultilayers in comparison with standard Fourier Transform and Atom Force Microscope methods.We express our gratitude to the Materials for Photovoltaic and Photonics Laboratory of the Institute of Applied Physics of the Academy of Sciences of Moldova for the samples preparing. Funding of work: the H2020-TWINN-2015 HOLO-project (687328); the Academy of Finland project 287150, 2015-2019

Comparative analysis of genetic polymorphism in <i>Rhaponticum carthamoides</i> (Asteraceae) populations by ISSR markers in the Altai Republic

Background. Rhaponticum carthamoides (Willd.) Iljin (Asteraceae) is a rare species for the Altai Republic (AR).  The purpose of this study was to characterize the genetic polymorphism of Rhaponticum carthamoides at the inter- and intrapopulation level in a comparative analysis for subsequent selection of seed samples from the genetically most heterogeneous natural populations of the AR for practical purposes.   Materials and methods. The species was studied for ISSR variability in five habitats in the AR. DNA from dried leaves of R. carthamoides was isolated using the STAB method. For testing seventeen ISSR primers were used, seven of which were selected as most informative ones.   Results and conclusion. The analysis showed that individual plants from five cenopopulations (CP) were distributed into three groups of similarity on the dendrogram. A separate clade was formed by plant samples from two CPs of the Katun Nature Reserve (KNR). Samples of one of those CPs grew on well-warmed southern slopes and exhibited a higher genetic heterogeneity than the others. The highest intrapopulation and interpopulation similarity in the distribution of DNA fragments was also found in two CPs from habitats with the smallest geographic distance from each other. Representatives of a separate population, least in size and number of individuals in the KNR, showed a high level of similarity in the distribution of DNA fragments. Significantly lower coefficients of genetic similarity with other CPs were found in plants from a small isolated CP from the Shavlinsky Protected Area. It can be assumed that one of the main reasons for the least genetic similarity of this population with others is its location in the immediate vicinity of the foothill at the pass to Achik (Ongudaysky District; absolute height: 2300 masl). This location can be a limiting factor for the exchange of genetic information with individuals from other populations

Direct magnetic and surface relief patterning using carbazole-based azopolymer

The results on using of carbazole-based azopolymer layers (Polyepoxypropylcarbazole:Methyl Red with magnetic particles of Fe2SO4) for the recording of 1-D and 2-D surface relief gratings are presented in this report. Morphology study using AFM and MFM of obtained structures has shown their good quality. Surface relief gratings with profile height up to 1.2 µm were obtained during the holographic recording using blue laser. Along with surface relief grating it was shown the direct formation of magnetic relief. Possibility of simultaneous direct fabrication of surface and magnetic relief by optical holographic recording using azopolymer thin films as recording media was shown

Direct Magnetic Relief Recording Using As40S60: Mn–Se Nanocomposite Multilayer Structures

Abstract Processes of holographic recording of surface relief structures using As2S3:Mn–Se multilayer nanostructures as registering media were studied in this paper. Optical properties of As2S3:Mn, Se layers, and As2S3:Mn–Se multilayer nanostructures were investigated. Values of optical bandgaps were obtained from Tauc dependencies. Surface relief diffraction gratings were recorded. Direct one-stage formation of surface relief using multilayer nanostructures is considered. For the first time, possibility of direct formation of magnetic relief simultaneous with surface relief formation under optical recording using As2S3:Mn–Se multilayer nanostructures is shown

Surface relief formation in Ge5As37S58–Se nanomultilayers

For the first time direct one-step relief formation of holographic grating with the use of amorphous chalcogenide nanomultilayers of new composition based on Ge5As37S58–Se was studied. Amorphous Ge5As37S58–Se nanomultilayers were prepared by cyclic thermal vacuum deposition. Optical constants of Ge5As37S58–Se nanomultilayers, Ge5As37S58 and α-Se films were obtained from transmission spectra. AFM and Raman investigations were performed for morphology and structural characterization on pointed films. Holographic diffraction gratings with diffraction efficiency of 18% in transmission measured at wavelength λ = 650 nm were directly recorded in one step without etching. High quality of grating sinusoidal relief up to ~ 100 nm groove depth was studied by AFM