| Thermal Expansion of Ternary Ge-Sb-Se Chalcogenide Glasses in Compositional Range for Molded Infrared Lens Applications |
| Mr. Junho Lee |
| Korea Aerospace University |
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| With the increasing demand upon the night vision system (infrared camera, for example) for use in transportation and surveillance, in addition to its existing military applications, cost effectiveness of IR transmitting lens becomes rapidly critical. As such, inorganic glasses that can be molded into lenses are certainly competitive against their crystalline counterparts such as Ge and ZnSe. Se-based chalcogenide glasses are being considered as the material of choice for optical-grade lenses operating at mid-infrared wavelength region around ~10 um. Among several selenide glass systems, ternary Ge-Sb-Se system is very promising as a moldable glass material owing to its thermal and mechanical stability [1, 2]. Glass formation out of this ternary system has been known, and various aspects of this unique glass have been studied so far. Compositional dependence of properties related to such a molding process needs to be investigated in order to optimize suitable compositions [3]. As for such composition-dependent properties, thermal expansion coefficient is definitely one of important parameters that should be taken into consideration. We recognize, however, that thermal expansion behavior of ternary Ge-Sb-Se glass in the compositional range targeting the molding process has not been studied systematically. Based on this consideration, we have aimed to evaluate its compositional dependence of thermal expansion coefficient. The measured thermal expansion data are analyzed as a function of content of each constituent atom, and then correlated with structural parameters such as mean coordination number and average bond energy. References: [1] X.H. Zhang, Y. Guimond and Y. Bellec, J. Non-Cryst. Solids 326&327 (2003) 519. [2] D.H. Cha, H.J. Kim, H.S. Park, Y.H. Hwang, J.H. Kim, J.H. Hong and K.S. Lee, Appl. Opt. 49 (2010) 1607. [3] J.K. Park, J.H. Lee, S.Y. Shin, J.H. Yi, W.H. Lee, N.Y. Kim and Y.G. Choi, Arch. Metall. Mater. (2014) accepted. |
| Acknowledgements : this work was supported by the Technology Innovation Program funded by the Ministry of Trade, Industry and Energy (Grant No. 10043803). |
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