SF11

BK7, SF11, LaSFN9, BaK1, and F2 are the most important optical and physical constants for Schott optical glass types. These types are used in most Dream Lasers simple lens products and prisms. The most commonly required chemical characteristics and mechanical constants, are listed. Further numerical data and a more detailed discussion of the various testing processes can be found in the Schott Optical Glass catalog.

SF11 Constants
Abbé Constant
25.76
Density
4.74 g/cm-3
Young's Modulus
6.60 x 109 dynes/mm2
Poisson's Ratio
0.235
Coefficient of Thermal Expansion (-30° to +70°C)
6.1 x 10-6/°C
Coefficient of Thermal Expansion (20° to 3000°C)
6.8 x 10-6/°C
Stress Birefringence, (Yellow Light)
10 nm/cm
Melt-to-Melt Mean Index Tolerance
±0.001
Homogeneity within Melt
±1x10-4
Striae Grade (MIL-G-174-A)
A
Transformation Temperature
505°C
Climate Resistance
1
Stain Resistance
0
Acid Resistance
1.0
Alkali Resistance
1.2
Phosphate Resistance
1.0
Knoop Hardness
450
Dispersion Constants
B1 = 1.73848403 
B2 = 3.11168974x10-1 
B3 = 1.17490871
C1 = 1.36068604x10-2 
C2 = 6.15960463x10-2 
C3 = 1.21922711x102
The external transmittance of SF11 is shown in the figure below:
External transmission for 10-mm-thick SF11 glass