Descriptions:
HGO grows LiF crystal lithium fluoride. LiF crystal or lithium fluoride crystal
is an optical material with outstanding transmittance in VUV region. It is widely used for windows, prisms, and lenses in the visible and infrared in
0.104µm-7µm.
Main
application:
1)
X-ray monochromator plates UV photomultiplier tubes
2)
Optical material for VUV applications
3)
Windows, prisms, and lenses
Main Features:
1)
Tends to create color centers.
2)
Max temperature for application:400°C
3)
Excellent VUV region transmittance
4)
Sensitive to thermal shock
Optical properties
of LiF crystal:
|
Transmission Range
|
0.105 … 6 µm
|
|
Refractive Index
|
no = 1.37327@2.5µm, 1.624@0.12 µm
|
|
Reflective Loss
|
4.4% @4.0 µm
|
|
Poisson Ratio
|
0.326
|
|
Absorption Coefficient/cm-`1
|
0.74×10-3@2.7µm
|
Basic
properties of LiF crystal:
|
Density
|
2.64g/cm3
|
|
Melting Point
|
870℃
|
|
Molar Mass
|
25.9394
|
|
Lattice Parameters
|
4.0279 Å
|
|
Thermal Conductivity
|
4.01 W/(m K)
|
|
Specific Heat
|
1562 (J kg-1 K-1)
|
|
Thermal Expansion Coefficient
|
28.1 - 34.8 (10-6/K)
|
|
Knoop Hardness
|
102–103kg/mm2
|
|
Mohs Hardness
|
3
|
|
Young's Modulus
|
64.79 GPa
|
|
Shear Modulus
|
55.14 GPa
|
|
Bulk Modulus
|
62.03 GPa
|
|
Rupture Modulus
|
10.8 MPa
|
|
Elastic Coefficient
|
C11 = 112 / C12 = 45.6 / C44 = 3.2 GPa
|
|
Crystal Type
|
Fm3m, cubic, NaCl type structure
|
|
Dielectric Constant
|
9.0 @ 25 °C, f = 100...109 Hz
|
|
Solubility in Water
|
0.27 (g/100 cm3) @ 18 °C
|
|
Apparent Elastic Limit/ MPa
|
11.2@1620 psi
|
|
Cleavage
|
-100
|
HGO offers LiF specifications:
|
Orientation:
|
<100>
|
|
Wavefront Distortion:
|
λ/4per inch @ 632.8 nm
|
|
Dimension Tolerances：
|
rods with diameter: +0.0/-0.05 mm , Length: ±0.1
mm
|
|
Surface Quality:
|
20/10 Scratch/Dig MIL-O-1380A
|
|
Parallelism:
|
< 20″
|
|
Perpendicularity:
|
< 10′
|
|
Clear Aperture:
|
> 90%
|
|
Surface Flatness:
|
< λ/8 @ 632.8 nm
|
|
Chamfer:
|
< 0.25 mm @ 45deg.
|
|
Size
|
Upon customer request
|
|
Quality Warranty Period
|
One year under proper use
|
Why
Choose HGO ?
HG OPTRONICS.,INC. is one of few growers who LiF crystals
in house. The use of high quality starting materials for crystal growth, whole
boule interferometry, precise inspection of scattering particle in crystal
using He-Ne laser and delicated measurement of bulk losses using
spectrophotometer assures that each crystal will comply with customer’s specification and perform well.
In addition, we can also produce other types of window
crystals like YAG crystals, BaF2,MgF2 Crystals, etc.
