REDUCED STRIAE LOW EXPANSION GLASS AND ELEMENTS, AND A METHOD FOR MAKING SAME

摘要

The invention is directed to a low expansion glass with reduced striae, the glass have a point-to-point variation in titania content is 0.1 wt % or less through its thickness and a CTE of 0±3 ppb/° C. in the temperature range 5-35° C. The invention is further directed to a method for producing the low expansion glass by using a method in which the time for repetition of the oscillation patterns used in the process are 10 minutes or less. In addition, the low expansion glass of the invention can have striae further reduced by heat-treating the glass at temperatures above 1600° C. for a time in the range of 48-160 hours.