CaF2 Crystals  

(Calcium Fluoride)

CaF2is a cubic crystal with an excellent transmission from 130 nm to 10 μm and has widespread applications as transparent windows in the ultraviolet and infrared spectra. Recently, CaF2 windows found a wide use for broadband continuum generation (white light generation) pumped by femtosecond lasers. HGO supplies [001] cut (i.e. the surface is perpendicular to the [001] axis) high quality CaF2 windows for continuum generation.  CaF2 windows cut along a random orientation and polycrystalline CaF2 are also available.


Basic Properties

Transparency Range: 130 - 9000 nm

Transmission Curve

Crystal Symmetry: Cubic

Density: 3.18 g/cm3 

Thermo-Optic Coefficients:
dn/dT= -13.1 x 10-6 /oC

Optical Homogeneity: Δn < 10-6/cm

Mohs Hardness:  4

Thermal Conductivity:  10 W/m/K

Thermal Expansion Coefficients:

α= 18 x 10-6/K

Sellmeier Equations (λ in µm):
n2= 1+ 0.56759λ2/(λ2 - 0.00253 ) + 0.47109λ2/(λ2-0.01001) + 3.84847λ2/(λ2-1200.56000)





[001] (-C), random (-R) or as specified

Dimension Tolerance:


Clear Aperture:

> 85%


< 10 arc sec (T>=2mm)
< 60 arc sec (T=<1mm)


λ/6 @ 632.8nm

Surface Quality:

20/10 Scratch and Dig

Transmission Wavefront Distortion:

< λ/6 @632.8nm


< 0.25mm X 45°


 upon customers’request


Ntoe: HG can also produce a wide variety of custom products (round/square lens or windows etc.) upon request.