Sapphire Al2O3

Crystaltechno Ltd. manufactures the following Sapphire optics: blanks, windows (plates), protective windows, optical polishing sapphire domes, spherical plano-convex lenses. Sapphire Al2O3 optics - transparent in wide spectral range from 0.17 to 5.5 microns.

Single crystal sapphire Al2O3 possesses a unique combination of excellent optical, physical and chemical properties. The hardest of the oxide crystals, sapphire Al2O3 retains its high strength at high temperatures, has good thermal properties and excellent transparency. Sapphire Al2O3 optics is chemically resistant to many acids and alkalis at temperatures up to 1000 degrees C as well as to HF below 300 degrees C. These properties encourage its wide use of Sapphire Al2O3 optics in hostile environments where optical transmission in the range from the visible to the near infrared is required.

Now the majority of crystals are growing from liquid melt. The most suitable substances to grow crystal from a melt have to melt without decomposition, have no polymorphic transitions and are characterized by low chemical activity. The crystallization process from a melt is applied in the most widespread methods of monocrystalline sapphire growth: namely, the Horizontally Directed Crystallization (HDC) method and Stepanov's method.

Stepanov's method is used for growth of monocrystal sapphire details of various configurations, including sapphire rods, pipes and tapes.

The method of Horizontally Directed Crystallization is widely used in the synthesis of large sapphire monocrystals. The elements of the directed crystallization and zonal melting are successfully combined in the Gorizontally Directed Crystallization (HDC) method. The crystal grows at slow movement of the local melted zone along the container with the furnace charge, having a boat form. The Horizontal Directed Crystallization method provides receiving of monocrystalline sapphire with small sizes dispersion of cross section and allows to grow up sapphire monocrystal of any crystallographic orientation in the form of plates of the record sizes unattainable at use of other growth methods.

The main application of optical sapphire is large aperture windows, viewports, illuminators for common-aperture optical systems (visible+IR) what make sapphire the top actual material due to its optical and mechanical properties.

Sapphire products are used in many fields as optical details (windows, plates, light guides and lenses, especially sapphire plane-parallel plates - windows, optical high-temperature substrates, exact mechanics details, bulbs of high pressure lamps and so on.

Crystaltechno Ltd. produces the different Large-sized Sapphire Windows-Plates with composite geometrical shape profile. Maximum sapphire plates sizes are 350x500x30 mm.

Besides, the optical polishing of Sapphire Dome - Hyper Hemisphere in diameter 200mm height 140mm is successfully finished at our optical shop. Now we can manufacture domes of any shape and any sizes from sapphire and other materials: CVD-ZnSe, CVD-ZnS, silicon, Ge, CaF2, BaF2, MgF2, LiF, fused silica and glass.

Our optical products have aroused customer’s interest of especially large-sized optics from sapphire with antireflection coating, namely: AR coated sapphire domes and AR broadband coated sapphire protective plates with composite geometrical shape profile.

We would like to offer the following products from sapphire: blanks, windows, tubes, rods, domes and lenses.

Perhaps you will find required Sapphire optics at our stock, please see item Optical Crystals.

The following products from Sapphire are available: BLANKS, WINDOWS, LENSES.


  Transmission Range   0.17 to 5.5 microns  
  Refractive Index   1.75449 (o) 1.74663 (e) at 1.06 microns  
  Reflection Loss   at 1.06 microns (2 surfaces) for o-ray - 11.7%; for e-ray - 14.2%  
  Index of Absorption   0.3 x 10-3 cm-1 at 2.4 microns  
  dN/dT   13.7 x 10-6 at 5.4 microns  
  dn/dm = 0   1.5 microns  
  Density   3.97 g/cm3  
  Melting Point   2040 degrees C  
  Thermal Conductivity   27.21 W/(m x K) at 300 K  
  Thermal Expansion   5.6 x 10 -6 /K (parallel C-axis) & 5.0 (perpendicular C-axis) x 10 -6 /K  
  Hardness   Knoop 2000 kg/mm 2 with 2000g indenter  
  Specific Heat Capacity   419 J/(kg x K)  
  Dielectric Constant   11.5 (parallel C-axis) 9.4 (perpendicular C-axis) at 1MHz  
  Young's Modulus (E)   335 GPa  
  Shear Modulus (G)   148.1 GPa  
  Bulk Modulus (K)   240 GPa  
  Elastic Coefficients   C11=496 C12=164 C13=115
C33=498 C44=148
  Apparent Elastic Limit   275 MPa (40,000 psi)  
  Poisson Ratio   0.25  
  Solubility   98 x 10-6 g/100g water  
  Molecular Weight   101.96  
  Class/Structure   Trigonal (hex), R3c  

Wavelength, µ m Refractive Index no Refractive Index ne
  0.193   1.92879   1.91743  
  0.213   1.88903   1.87839  
  0.222   1.87540   1.86504  
  0.226   1.87017   1.85991  
  0.244   1.85059   1.84075  
  0.248   1.84696   1.83719  
  0.257   1.83932   1.82972  
  0.266   1.83304   1.82358  
  0.280   1.82437   1.81509  
  0.308   1.81096   1.80198  
  0.325   1.80467   1.79582  
  0.337   1.80082   1.79206  
  0.351   1.79693   1.78825  
  0.355   1.79598   1.78732  
  0.442   1.78038   1.77206  
  0.458   1.77843   1.77015  
  0.488   1.77530   1.76711  
  0.515   1.77304   1.76486  
  0.532   1.77170   1.76355  
  0.590   1.76804   1.75996  
  0.633   1.76590   1.75787  
  0.670   1.76433   1.75632  
  0.694   1.76341   1.75542  
  0.755   1.76141   1.75346  
  0.780   1.76068   1.75274  
  0.800   1.76013   1.7522  
  0.820   1.75961   1.75168  
  0.980   1.75607   1.74819  
  1.064   1.75449   1.74663  
  1.320   1.75009   1.74227  
  1.550   1.74618   1.73838  

Besides we offer round Sapphire Al2O3 optics (windows, lenses and blanks) of available size up to 300 mm dia. and square. Maximum sapphire plates (windows, blanks) sizes are 350x500x30 mm.

Sapphire Al2O3 optics is also available in the following forms, namely

  • Sapphire Al2O3 round rod (2-20 mm dia., 150-300 mm long)
  • rectangular and square Sapphire Al2O3 rod
  • Sapphire Al2O3 ribbon (10-80 mm wide, 1-4 mm thick, 150-300 mm long)
  • Sapphire Al2O3 tubes (3-30 mm dia., 1-8 mm wall thickness, 150-300 mm long) and other custom cross-section configurations of Sapphire Al2O3 optics.


Polished Domes

Sapphire Optics Windows Dome Crystaltechno

Sapphire Large Windows Crystaltechno

Sapphire Tube Crystaltechno

Large Sapphire Window Crystaltechno

Sapphire Dome Crystaltechno

Sapphire Window Crystaltechno

Sapphire Optics Blanks Window Crystaltechno

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