Transmissivities were measured and absorption coefficients derived for three types of fused quartz between room temperature and 1500°C: GE uv Type 151 (0.21–2.0 μ), GE ir Type 105 (0.21–3.5 μ), and Corning Vycor ir glass No. 7905 (1.7–4.0 μ). Less extensive measurements were also performed with Corning uv Type 7940. The interval of virtual transparency (transmissivity ≳ 0.85) of each type between the ultraviolet and near-infrared was reduced by heating due to a shift in both the long- and short-wavelength absorption edges.
E. C. Beder, C. D. Bass, and W. L. Shackleford, "Transmissivity and Absorption of Fused Quartz Between 0.22 μ and 3.5 μ from Room Temperature to 1500°C," Appl. Opt. 10, 2263-2268 (1971)