Colorless sulfide glasses can be obtained by selecting appropriately the composition within the Ga₂S₃-GeS₂-CsCl pseudo-ternary glass system. The addition of electronegative chlorine ions into the sulfide glassy network results in a widening of its optical bandgap without altering its infrared transparency. Glasses transparent from the near UV (380 nm) up to the middle infrared (11.5 μm) are thus achievable. Such extended infrared transmission for a colorless glass is the widest among the known heavy metal oxide and fluoride glasses, e.g. fluoroindate glasses are transparent from 350 nm up to 8-9 μm. We present in this work our recent progress on the preparation of this chloro-sulfide glass of high optical quality. Efforts have been devoted in a first step to reduce the content of extrinsic impurities such as OH, SH and H₂O. In a second step, protective coatings have been deposited on polished glass samples to improve their chemical durability and assess their potential for practical applications. Large improvement of both optical quality, in terms of transmission spectrum flattening, and chemical durability were achieved. Finally, the high thermal stability against crystallization of this glass shows a high potential for lens molding and applications in multispectral imaging.

Date Published: 25 September 2013
PDF: 8 pages
Proc. SPIE 8847, Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications VII, 884704 (25 September 2013); doi: 10.1117/12.2024461

Published in SPIE Proceedings Vol. 8847:
Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications VII
Shizhuo Yin; Ruyan Guo, Editor(s)