OPTICS CRYSTALS LASERS
   
 
Borosilicate Crown Glass BK7

Glass BK7 - the colourless optical glass, it differs high degree of uniformity, is steady in relation to carbonic acid action, well keeps the form and is easily processed. Glass BK7 is one of the basic materials for manufacturing of optical details for the lasers of visible and near IR spectrum range. The spectral transmittance of glasses BK7 is shown. Elektrosteklo Ltd. manufactures different kinds of optics from the glass BK7, namely, the plane-parallel plates (window), lens, prisms, spherical lenses, cylindrical lenses, the mirrors both under the catalog and the customer’s specification.

BASE PROPERTIES

PARAMETER VALUE
OPTICAL  
  Refractive Index of the glass BK7   nd=1.51680; ne=1.51872  
  Abbe Constant   Ad = 64.17; Ae = 63.96  
  Principal Dispersion   nF - nC = 0.008054
nF' - nC' = 0.008110
 
  Bubble class   0  
         
PHSYCAL  
  Density   2.51 g/cm3  
  Transformation Temperature, Tg   557° C  
  Temperature of glass in at a viscosity of 107.6 dPa s   719° C  
  Thermal Conductivity   1.114 W/(m*K)  
  Coefficient of Expansion   7.1 x 10-6/K -30° ... +70° C
8.3 x 10-6/K 20° ... 300° C
 
  Knoop hardness (0.1/20)   610  
  Specific Heat Capacity   0.858 J/(g*K)  
  Young's Modulus (E)   82 x 103 N/mm2  
  Stress optical coefficient   2.77 x 10-6 mm2/N  
  Poisson's Ratio   0.206  
CHEMICAL  
  Climatic resistance   2  
  Stain resistance   0  
  Acid resistance   1  
  Phosphate resistance   2.3  
  Alkali resistance   2.0  

REFRACTIVE INDEX of the glass BK7

  Wavelength, nm 2325.4 1970.1 1529.6 1060.0 1014.0 852.1 706.5  
  Refractive Index 1.489 1.495 1.501 1.507 1.507 1.510 1.513  
  Wavelength, nm 656.3 643.8 632.8 589.3 587.6 546.1 486.1  
  Refractive Index 1.514 1.515 1.515 1.517 1.517 1.519 1.522  
  Wavelength, nm 480.0 4358 404.7 365.0 334.1 312.6  
  Refractive Index 1.523 1.527 1.530 1.536 1.543 1.549  


Relative partial dispersion of glass BK7

  P(s,t)   0.3098  
  P(C,s)   0.5612  
  P(d,C)   0.3076  
  P(e,d)   0.2386  
  P(g,f)   0.5349  
  P(i,h)   0.7483  
  P(s,t)   0.3076  
  P(C',s)   0.6062  
  P(d,C')   0.2566  
  P(e,d)   0.2370  
  P(g,F')   0.4754  
  P(i,h)   0.7432  

 



 
 
 
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Windows
Wedges
Plano-Convex Lenses
Bi-Convex Lenses
Bi-Concave Lenses
Meniscus
Cylinder Lenses
Right Angle Prisms
Dispersion Prisms
Corner Cube Retroreflectors
Penta Prisms

Ordering Info
 
  (c) Crystaltechno Ltd. Vernadskogo 113-106, Moscow 119571, Russia
+7 (495) 234-5951, 234-5952, 956-7610
fax +7 (495) 433-1551
sales@crystaltechno.com
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