Corning® HPFS®7979 Fused Silica

Optical Materials Product Information

Corning 7979 is high purity non-crystalline silica glass with excellent optical qualities produced by Corning Company. The material is with extraordinary low refractive index variations leading to state-of-the-art homogeneity values, lowest birefringence values, large size capabilities, exceptional transmittance from the deep ultraviolet through the infrared region, and an ultra-low thermal expansion coefficient. The detail specification of Corning 7979 fused silica is as follows:

Attribute	7979 IR Grade	7979 Industrial Grade
Visible Transmittance	*	*
UV Transmittance
Infrared Transmittance	*
Homogeneity Certified in Use-Axis: AA, A, C, F (By Size)	*
Inclusion Class: 0, 1, 2, 5	*
Striae: ISO 10110-4 Class 5 (None)	*
Homogeneity Certified in Off-Axis: AA, A, C, F (By Size)	*
Low Birefringence	*
UV Laser Resistance (data available upon request)
Economical (No certification of any properties except visible transmission and birefringence. Tooling applications.)		*

Quality Grade Selection Chart

Attribute	ISO 10110-1 Inclusion Class	Homogeneity Grade [ppm]	Birefringence Lower specifications available upon request [nm/cm]	ISO 10110-4 Striae Class	Metallic Impurities [ppb]	OH Content [ppm]
7979 IR Grade	0, 1, 2	AA, A, C, F	≤5	5	<100	<1
7979 Industrial Grade	NS	NS	≤5	NS	NS	NS

Mechanical Properties