Issue Information

Glass melts are considered commercially relevant once their melt size exceeds nominally 0.5 kg.Large melts are necessary when a particular glass system is selected to mass produce optical elements, such as windows, lenses, and filters.However, melt homogeneity and glass stability are sensitive to changes in melt size.In our study, a 2.5 kg glass plate (A) was manufactured by Amorphous Materials Inc., allowing the comparison of thermal behavior of this melt to previously demonstrated lab-scale melts.By segregating this plate into multiple cores (B), the material response to thermally-induced crystallization can be evaluated as a function of position within the plate.Individual specimens (C) were converted to glass-ceramics and their change in refractive index (relative to the base glass) was measured.Ongoing efforts seek to demonstrate index changes across the mid-and long-wave infrared, thus enabling dispersion engineering essential for designing imaging systems with reduced footprint and manufacturing costs.