| Chalcogenide glass is an anaerobic infrared glass composed of three elements of VIA family S,Se and Te in the periodic table of elements and metal elements such as Ge,Ga,As and Sb.Chalcogenide glass has attracted more and more attention and research due to its unique optical and electrical properties.Chalcogenide glass is characterized by its high linear refractive index,ultra-short response time(<200 fs),high infrared transmittance,short research and development period,and safe and non-toxic elements selected from raw materials.Above all,chalcogenide glass has very high third-order nonlinearity,which makes it have great potential and research value in the fields of optical information processing,electro-optical switch,laser protection.However,the research based on chalcogenide glass mainly focuses on the fields of optical communication devices and ultra-fast all-optical switches,while there are few studies on the electro-optical control characteristics of chalcogenide glass.In this paper,the phase difference of the two components of the incident light caused by the field-induced birefringence is calculated by analyzing the intensity change of 980 nm light through the bulk Ge28Sb12Se60 sample under different applied electric field intensities.The direct current Kerr coefficient K=-8.2383 ×10-14 m/V2 of the Ge28Sb12Se60 sample is obtained.The results show that Ge28Sb12Se60 has a large DC Kerr factor,which is two orders of magnitude higher than that of oxide glass,making it very advantageous in the preparation of high-speed electro-optical modulator or other devices in the related infrared band.In this paper,the electroabsorption behavior of Ge28Sb12Se60 sample was studied by applying different intensity external electric fields to the sample,and the change of transmitted light intensity caused by electroabsorption was measured.Based on this effect,the imaginary part of DC Kerr coefficient Ki=3.86939×10-18m/V2 was calculated.It shows that the imaginary part of Kerr constant can be effectively measured and controlled within a certain electric field range,which provides valuable reference for related applications.In this paper,Ge28Sb12Se60 thin film samples of chalcogenide glass were prepared by vacuum thermal evaporation.Silver films were used as electrodes to change the optical isotropy by applying an electric field to Ge28Sb12Se60.The theoretical deduction of the free space coupling method is given,and the relationship between the applied electric field E and the reflectance of Ge28Sb12Se60 film sample is obtained.Based on the theory of free spatial coupling,the measuring optical path is designed,and the corresponding reflectance change ΔR is measured under TM and TE modes respectively.The second electro-optical coefficients S11 S12 and S44 of Ge28Sb12Se60 film can be obtained,and the DC Kerr coefficients of Ge28Sb12Se60 film are obtained by K=-3.3805 × 10-13m/V2. |
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