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Magnesium fluoride(MgF2) window

Magnesium fluoride(MgF2) window

Magnesium fluoride(MgF2) optical window


 Single crystal of Magnesium fluoride(MgF2)
 Polycrystalline of Magnesium fluoride(MgF2)
 Purity: >99.99%

Other Names

Magnesium fluoride window, MgF2 window, MgF2 wafer, MgF2 plate

Applicable wave band

0.11um ~ 7.5um

Refractive Index

no=1.37608 ne=1.38771

Melting Point

Thermal Conductivity (W/K.m)


Kirschner Hardness (/kg*mm-2)


Elasticity Coefficient


Thermal expansion coefficient

13.7×10-6 (∥c),8.9×10-6 (⊥c)

Maximum size

 Diameter 100mm (Single crystal)
 Diameter 200mm (Polycrystalline)

Material Standard Size Surface quality
Magnesium fluoride(MgF2) window

(Single crystal window) or
(Polycrystalline window)
φ5.0mm x 1.0mm
φ25mm x 1.0mm
φ25.4mm x 2.0mm
φ50mm x 3.0mm
φ50.8mm x 0.5mm
φ50.8mm x 2.0mm
φ100mm x 1.0mm
φ100mm x 3.0mm
10 x 10 x 1.0mm
20 x 20 x 2.0mm
Polishing:             Double side optical polished or Epi-polished
Roughness:          Ra<0.5nm, Ra<1nm or Ra<5nm
Size Tolerance:          +/-0.1mm
Thickness Tolerance: +/-0.1mm or +/-0.05mm
Parallelism:           3 minutes, 1 minute, 30 seconds or higher
Surface Finish:      60-40, 40-20, 20-10 or others
Surface Figure:      1/2λ, 1/4λ or higher
Chamfer:                0.25mm × 45°

Magnesium fluoride(MgF2) is Tetragonal crystal system with  high hardness, good mechanical properties, stable chemical properties, not easy to deliquesce and corrosion, and its main characteristics in optical properties are its high transmittance in the vacuum Ultraviolet band (transmittance is still >50% in 120nm ), Magnesium fluoride(MgF2) suitable for windows and focusing mirrors of deep ultraviolet and excimer lasers. In addition, because of it is a Tetragonal birefringent crystal, it is widely used in optical components such as fiber optic communications and wave plates.
The refractive index of Magnesium fluoride(MgF2) window is about 1.38, which can be used as Laser window, Ultraviolet window, Infrared window / substrate material, etc. Magnesium fluoride(MgF2) window is excellent in the ultraviolet band, it is the most important low refractive index window material,

We can customize different size and thickness of Magnesium fluoride(MgF2) optical window upon requirements, such as Magnesium fluoride(MgF2) round wafer, Square substrate and Cylinder, or Punch holes and other shapes.
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Contact Us

  • Biotain Crystal Co., Ltd.
  • Tel: (+86) 1506 0796 451
  • Fax: (+86) 597 2212602
  • Email:
  • Work Time ( GMT +8 ):
  •    9 AM ~ 6 PM, Monday to Friday
  • Main office: A7-13Z, No. 501, Denggaoxi Road, Xipi street, Xinluo District, Longyan, Fujian, China