Publikationsdatum:
2017-09-06
Beschreibung:
For fiber-optic mid-infrared bio- and chemical-sensing, Ge-Sb-Se glass optical fibers are more attractive than Ge-As-Se because of: (i) lowered toxicity and (ii) lower phonon energy and hence transmission to longer wavelengths, with potential to reach the spectral ‘fingerprint region’ for molecular sensing. There is little previous work on Ge-Sb-Se fibers. Here, fibers are fabricated from two glass compositions in the Ge x Sb 10 Se 90-x atomic (at.) % series. Both glass compositions are of similar mean-coordination-number, lying in the overconstrained region, yet of different chemical composition: stoichiometric Ge 25 Sb 10 Se 65 at. % and non-stoichiometric Ge 20 Sb 10 Se 70 at. %. Thermal analysis on bulk glasses has previously shown that the former exhibited the maximum glass stability of the series. However, during fiber-drawing of Ge 25 Sb 10 Se 65 at. %, the preform tip is found to undergo surface-devitrification to monoclinic GeSe 2 alone, the primary phase, no matter if the preform is an annealed, as-melted rod or annealed, extruded rod. The heating rate of the preform-tip to the fiber-drawing temperature is estimated to be up to ~ 100 °C min −1 to ~ 490 °C. Lower heating rates of 10 °C min −1 using thermal analysis, in contrast, encourage crystallization of both Sb 2 Se 3 and GeSe 2 . The non-stoichiometric: Ge 20 Sb 10 Se 70 at. % composition drew successfully to low optical loss fiber, no matter whether the preform was an annealed, as-melted rod or annealed, extruded rod. This article is protected by copyright. All rights reserved.
Print ISSN:
0002-7820
Digitale ISSN:
1551-2916
Thema:
Maschinenbau
