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Optical Glass Properties

Corning 7980 and 7940 Wafers & Substrates

Fused Silica Wafers (Corning 7940 & 7980)
Fused silica Corning 7940 wafer material has been discontinued by Corning and was replaced by HPFS (High Purity Fused Silica) 7980, which is an ideal material for UV grade Fused Silica wafers. The two fused silica wafer materials are almost identical in composition, properties and transmission, and can be used interchangeably. The material is a high purity synthetic amorphous silicon dioxide which is manufactured by flame hydrolysis. Some beneficial characteristics include very low thermal expansion coefficient, very good homogeneity with excellent optical properties and exceptional transmittance in the UV range.

Principal Uses for UV Fused Silica

Laser optics, optical grade UV Fused Silica windows and lenses, mirror blanks and substrates, wedges, optical beamsplitters and filters, prisms, lightpipes, space and aircraft windows, solar cells, high quality coating substrates and wafers, heater tubing, and graded seals.

Applications for Fused Silica Wafers

Common UV, low CTE, optoelectronic, high temperature, thermal imaging, measurement and sensor technology, astronomical, microlithography, MEMS, Excimer and Nd:YAG laser applications, and where superior grade fused silica wafers are needed.

Thermal/Mechanical Properties of Corning UV Grade Fused Silica

  • Coefficient of Thermal Expansion (CTE):
    0.52 ppm/K @ 5-35°C
    0.57 ppm/K @ 0-200°C
    0.48 ppm/K @ -100 – 200°C
  • Young’s Modulus: 72.1 GPa
  • Shear Modulus: 30.6 GPa
  • Modulus of Rupture, abraded: 52.4 MPa
  • Bulk Modulus: 37.4 GPa
  • Poisson’s Ratio: .179
  • Density (at 25°C / 77°F): 2.201 g/cm3
  • Knoop Hardness (100g load): 522 kg/mm2
  • Compressive Strength: 1.14 GPa
  • Tensile Strength: 54 MPa
  • Strain Point: 893°C/1639.4°F
  • Annealing Point: 1042°C/1907.6°F
  • Softening Point: 1585°C/2885°F
  • Specific Heat: .770 J/g K
  • Thermal Conductivity: 1.38 W/mK
  • Thermal Diffusivity: .0075 cm2/s

Optical Properties

Refractive Index: nD = 1,45840 (589nm)
Optical transmission

Electrical Properties

Dielectric Constant: E= 3.8

Many Fused Silica wafer sizes available from stock.

Other fused silica wafer related web pages:

Fused silica and fused quartz flat optics and windows
Fused silica and fused quartz wafers and substrates

Optically polished fused silica, fused quartz and single crystal quartz

Fused silica wafers and fused quartz substrates, windows and plates