UV Material
 Visible Material
 IR Material
 Color Material
 Sperical Material
 
Borosilicate Crown Glass (BK-7)

Borosilicate Crown Glass is used for windows, lenses, and prisms where transmission in the range 0.4µm to 1.4µm is desired. The refractive index varies from about 1.53 to 1.5 through this range. It is used for thermally non-critical applications.
 
Property
Specification
Transmission Range
0.4µm to 2.5µm
Density
2.51 g/cc
Thermal Expansion
7.1x10-6 /°K @ -30° + 70°C, & 8.3x10-6 /°K @ 20°C to 300°
Surface Finish
BK-7 polishes extremely well & polishes of 10-5, or 20-10 scratch-dig are achieved at extra costs respectively, mainly for UV & visible applications.
Surface Figure
Surface figure of 1/10 wave to 1/4 wave @ 0.6328µm are specified mostly on lenses for ultraviolet & visible use.
AR Coating Options
AR @ 0.8-2.5µm, AR @ 1.064, AR @ visible wavelength.
Typical Applications
Astronomical, Thermal Imaging
Products Manufactured
Lenses, Windows, Wedges, Prism, Beamsplitters, Filters.
 
Wavelength (µm)
Index of Refraction (n)
0.4047
1.530
0.4800
1.523
0.5461
1.519
0.6328
1.515
0.8521
1.510
1.0600
1.507
1.5300
1.501
1.9700
1.495
2.3250
1.489