Optical Nonlinear Properties Investigation Of Se-based Chalcogenide Glass Ceramics

In recent years,as human society has entered the era of high-speed information,the fields of all-optical communication,optical computing,optical storage,etc.are rapidly developing,and research requirements for passive components such as optical switches,wavelength converters,and optical filters are increasing.These devices must rely on materials with good nonlinear optical properties.Among many nonlinear optical materials,chalcogenide glass has good optical third-order nonlinear characteristics,and its nonlinear refractive index coefficient is 1000 times that of silica glass,and it is easy to process into optical fiber,film,and then into various devices.The chalcogenide glasses refer to the materials of glass network mainly composed of chalcogen elements(S,Se,Te)and introduced into elements of the main groups III,IV and V of the periodic table.The chalcogenide glass has an ultra-wide infrared transmission range,low optical loss,good thermal and structural stability,and a high nonlinear refractive index.For S-based glass,the infrared transmission spectrum is narrow,cutting off at 12 microns,and the thermal stability of Te-based glass is poor.As an intermediate element,Se consists of a glass that solves the above drawbacks.At the same time,the introduction of nanocrystalline particles by heat treatment in the matrix sulfur-based glass can further improve the thermodynamic and mechanical properties of the chalcogenide glass,and can also improve its third-order optical nonlinear performance.The main purpose of this paper is to prepare a series of Sn-Sb-Se chalcogenide glasses by melt quenching method.The mechanical properties,optical properties and structure of the glass components of the matrix are analyzed by subsequent tests.Causal relationship was systematically analyzed and discussed,and then Se-based glass-ceramics were obtained by heat treatment analysis in groups.After further analysis,the applicable glass-ceramic materials with high nonlinear properties were finally prepared.The details are as follows:(1)Study on the network structure,mechanical properties and optical properties of Sn-Sb-Se chalcogenide matrixglass.The mechanical properties of the glass of different compositions were obtained by testing the Vickershardness of the glass samples.The relationship between the mechanical properties of the matrix glass and theelemental composition was analyzed by the mean coordination number(MCN)theory.The results show thatwhen the MCN value is less than 2.4,the hardness increases with square or cubic MCN,and when MCN isgreater than 2.4,it remains almost unchanged.The Sb element obtained by the topological distribution ofelements is the key to improve the mechanical properties of the matrix glass.(2)Preparation,mechanical properties and optical properties of Sn-Sb-Se chalcogenide glass-ceramics.According to the previous research,the optimum composition Sn9.8Sb17.22Se72.98 and the comparativecomponent Sn6.23Sb14.11Se79.66 were determined,and the glass transition temperature Tg of the matrix glasswas obtained by DSC thermal analysis,to design the heat treatment temperature and duration.Chalcogenideglass ceramics were prepared through multiple experiments.By analyzing the relationship between Vickershardness,optical band gap Eopg and heat treatment durations,it is found that within a certain range,as the heattreatment duration increases,the mechanical property of the glass-ceramics increases and the Eopg valuedecreases.The results of XRD spectroscopy indicate that the generation and growth of Sb2Se3 crystals are theroot cause of the above changes.Study on linear and nonlinear optical properties of Sn-Sb-Se chalcogenide glass-ceramics.The linear refractive index of the prepared samples was measured from 1.7 to 15 ?m using an ellipsometer.The Z-scan technique is mainly used to test the third-order nonlinear refractive index of the glass-ceramics.The influence of structural changes on nonlinear optical parameters was analyzed by Raman spectroscopy.Finally,by comprehensively analyzing the experimental results,a Se-based chalcogenide glass material with high optical nonlinearity can be prepared.