Heavy metal fluoride glasses are of particular interest for laser window applications because they have negative thermo-optic coefficients dn/dT. A negative value of dn/dT leads to very low to near zero optical path distortion (OPD). Because heavy metal fluoride glasses are multi-component glass forming systems they offer a means to tailor properties through compositional variations in such a way that OPD can be controlled and minimized. This paper examines the effect of compositional changes of ZrF4 -based glasses on properties critical in determining OPD i. e. thermal expansion refractive index and dn/dT. In addition this paper describes a new interferometric technique used to measure CTE and dn/dT concurrently. The role various components play in determining the critical properties and the theoretical OPD is discussed. Finally the viability of using these compositional changes for the preparation of bulk glasses will be evaluated in terms of glass stability. 1.

Date Published: 1 October 1990
PDF: 8 pages
Proc. SPIE 1327, Properties and Characteristics of Optical Glass II, (1 October 1990); doi: 10.1117/12.22530

Published in SPIE Proceedings Vol. 1327:
Properties and Characteristics of Optical Glass II
Alexander J. Marker III, Editor(s)