Cluster analysis of component composition of essential oil taken from plants of FIlipendula genus

The different plants of Filipendula genus are sources of essential oil and are used in scientific or folk medicine very often. As a result of conducted research, it was established that the component composition of essentially oil are methylsalycylate and salicylic aldehyde and mono- and sesquiterpenes mainly. At the same time the quantitative content of separate components of essential oil were significantly differed. Further the means of data clustering have been applied which allowed to analyze the set of all experimental data simultaneously. Analysis of built hierarchical tree showed the researched plants can be integrated into 3 groups in accordance with degree of difference: 1 - F. camtschatica, F. glaberrima, F. palmata; 2 - F. ulmaria, F. denudata, F.picbaueri; 3 - F. vulgaris. Such distribution corresponds to taxonomy positions of these spesies of Filipendula genus. Thus, the proposed approach to analysis of the components composition of essential oil can be used as an additional sign in solving taxonomy tasks for dividing various species. Besides the cluster analysis of component composition of essential oils can be as a methodical basis of implementation of technology a "fingerprint" technology, which can be used for identification of not qualitative herb raw materials containing other plants.The different plants of Filipendula genus are sources of essential oil and are used in scientific or folk medicine very often. As a result of conducted research, it was established that the component composition of essentially oil are methylsalycylate and salicylic aldehyde and mono- and sesquiterpenes mainly. At the same time the quantitative content of separate components of essential oil were significantly differed. Further the means of data clustering have been applied which allowed to analyze the set of all experimental data simultaneously. Analysis of built hierarchical tree showed the researched plants can be integrated into 3 groups in accordance with degree of difference: 1 - F. camtschatica, F. glaberrima, F. palmata; 2 - F. ulmaria, F. denudata, F.picbaueri; 3 - F. vulgaris. Such distribution corresponds to taxonomy positions of these spesies of Filipendula genus. Thus, the proposed approach to analysis of the components composition of essential oil can be used as an additional sign in solving taxonomy tasks for dividing various species. Besides the cluster analysis of component composition of essential oils can be as a methodical basis of implementation of technology a "fingerprint" technology, which can be used for identification of not qualitative herb raw materials containing other plants

Exploring van der Waals materials with high anisotropy: geometrical and optical approaches

The emergence of van der Waals (vdW) materials resulted in the discovery of their giant optical, mechanical, and electronic anisotropic properties, immediately enabling countless novel phenomena and applications. Such success inspired an intensive search for the highest possible anisotropic properties among vdW materials. Furthermore, the identification of the most promising among the huge family of vdW materials is a challenging quest requiring innovative approaches. Here, we suggest an easy-to-use method for such a survey based on the crystallographic geometrical perspective of vdW materials followed by their optical characterization. Using our approach, we found As2S3 as a highly anisotropic vdW material. It demonstrates rare giant in-plane optical anisotropy, high refractive index and transparency in the visible range, overcoming the century-long record set by rutile. Given these benefits, As2S3 opens a pathway towards next-generation nanophotonics as demonstrated by an ultrathin true zero-order quarter-waveplate that combines classical and the Fabry-Perot optical phase accumulations. Hence, our approach provides an effective and easy-to-use method to find vdW materials with the utmost anisotropic properties.Comment: 11 pages, 5 figure

van der Waals materials for overcoming fundamental limitations in photonic integrated circuitry

With the advance of on-chip nanophotonics, there is a high demand for high-refractive-index and low-loss materials. Currently, this technology is dominated by silicon, but van der Waals (vdW) materials with a high refractive index can offer a very advanced alternative. Still, up to now, it was not clear if the optical anisotropy perpendicular to the layers might be a hindering factor for the development of vdW nanophotonics. Here, we studied WS2-based waveguides in terms of their optical properties and, particularly, in terms of possible crosstalk distance. Surprisingly, we discovered that the low refractive index in the direction perpendicular to the atomic layers improves the characteristics of such devices, mainly due to expanding the range of parameters at which single-mode propagation can be achieved. Thus, using anisotropic materials offers new opportunities and novel control knobs when designing nanophotonic devices.L.M.M. acknowledges Project PID2020-115221GB-C41, financed by MCIN/AEI/10.13039/501100011033, and the Aragon Government through Project Q-MAD. A.A.V., I.K., and D.I.Y. gratefully acknowledge the financial support from the Ministry of Science and Higher Education (Agreement No. 075-15-2021-606). I.A.K. gratefully acknowledges the financial support from the RSF (No. 22-19-00738) for first-principle calculations. K.S.N. is grateful to the Ministry of Education, Singapore (Research Centre of Excellence award to the Institute for Functional Intelligent Materials, I-FIM, project No. EDUNC-33-18-279-V12) and to the Royal Society (UK, grant number RSRP\R\190000) for support.Peer reviewe

Exploring van der Waals materials with high anisotropy: geometrical and optical approaches

Abstract The emergence of van der Waals (vdW) materials resulted in the discovery of their high optical, mechanical, and electronic anisotropic properties, immediately enabling countless novel phenomena and applications. Such success inspired an intensive search for the highest possible anisotropic properties among vdW materials. Furthermore, the identification of the most promising among the huge family of vdW materials is a challenging quest requiring innovative approaches. Here, we suggest an easy-to-use method for such a survey based on the crystallographic geometrical perspective of vdW materials followed by their optical characterization. Using our approach, we found As2S3 as a highly anisotropic vdW material. It demonstrates high in-plane optical anisotropy that is ~20% larger than for rutile and over two times as large as calcite, high refractive index, and transparency in the visible range, overcoming the century-long record set by rutile. Given these benefits, As2S3 opens a pathway towards next-generation nanophotonics as demonstrated by an ultrathin true zero-order quarter-wave plate that combines classical and the Fabry–Pérot optical phase accumulations. Hence, our approach provides an effective and easy-to-use method to find vdW materials with the utmost anisotropic properties

Wandering principal optical axes in van der Waals triclinic materials

Abstract Nature is abundant in material platforms with anisotropic permittivities arising from symmetry reduction that feature a variety of extraordinary optical effects. Principal optical axes are essential characteristics for these effects that define light-matter interaction. Their orientation – an orthogonal Cartesian basis that diagonalizes the permittivity tensor, is often assumed stationary. Here, we show that the low-symmetry triclinic crystalline structure of van der Waals rhenium disulfide and rhenium diselenide is characterized by wandering principal optical axes in the space-wavelength domain with above π/2 degree of rotation for in-plane components. In turn, this leads to wavelength-switchable propagation directions of their waveguide modes. The physical origin of wandering principal optical axes is explained using a multi-exciton phenomenological model and ab initio calculations. We envision that the wandering principal optical axes of the investigated low-symmetry triclinic van der Waals crystals offer a platform for unexplored anisotropic phenomena and nanophotonic applications

Data for manuscript "Wandering principal optical axes in van der Waals triclinic materials"

Data for manuscript "Wandering principal optical axes in van der Waals triclinic materials"</p