|
BK7 | Fused
Silica | Sapphire | CaF2
| MgF2 | Crystal
Quartz
BK7
BK7 is a borosilicate crown optical glass with high homogeneity, low bubble and inclusion
content. Its good physical and chemical properties
make it widely used in visible and near IR range.
Most of windows, lenses and prisms, which used in
laser, optical system, optical communication, are
made from BK7 glass.
- Transmission range: 330 nm~2100 nm
- Thermal Expansion Coefficient: 7.5X10-6
/K
- Density: 2.51 g/cm3
|
 |
Fused Silica
Fused Silica is formed by chemical combination of
silicon and oxygen. Fused Silica is perfect
optical material due to its good UV and IR
transmission, low coefficient of thermal
expansion. It has high stability and resistance to
thermal shock over large temperature excursions,
wide temperature operating range and high laser
damage threshold.
- Transmission Range: 185 nm~2500 nm
- Thermal Expansion Coefficient: 0.54X10-6/K
- Density: 2.20 g/cm3
|
 |
Sapphire
Sapphire is a single crystal aluminum oxide
(Al2O3). It is one of the hardest materials.
Sapphire has good transmission characteristics
over the visible, and near IR spectrum. It
exhibits high mechanical strength, chemical
resistance, thermal conductivity and thermal
stability. It is often used as window materials in
specific field such as space technology where
scratch or high temperature resistance is
required.
Physical
Properties
| Crystal
Symmetry Hexagonal |
|
System |
| Lattice
constant |
A |
a
=4.75 ;
c =12.97 |
| Transparence
range |
μm |
0.18-
4.5 |
| Density |
g/cm3 |
3.98 |
| Mohs hardness |
|
9 |
| Melting point |
oC |
2030 |
| Thermal
conductivity |
W/m/K |
0.04 |
| Expansion
coefficien |
10-6/K |
8.4 |
| Refractive
Index |
1.0
μm |
1.755 |
|
 |
CaF2
CaF2 is a crystal with good
transmission from 170 nm to 7800 nm. It is slightly
soluble in water and susceptible to thermal shock.
CaF2 is commonly used in IR components
such as windows, lenses and prisms.
- Transmission range: 170 nm~7800 nm
- Thermal Expansion coefficient: 18.85X10-6/K
- Density: 3.18 g/cm3
|
 |
MgF2
MgF2 is a birefrigent material crystal with
excellent physical and chemical properties. It
provides wide transparent range, high
transmissibility. It can be widely used as UV
material.
Main
Properties
| Lattice
constant |
a=4.621A;
c=3.053A |
| Mohs
hardness |
6 |
| Specific
weight |
1255 |
| Specific
weight |
3.18g/cm3 |
| Transparence
range |
0.12-8.5mm |
| Thermal
conductivity |
0.0075W/m/K |
| Expansion
coefficient |
aa=13.7x10-6/K;
ac=8.48x10-6/K |
| Refraction
Index |
0: 405m no=1.3836, ne=1.3957
1: 1.55mm no=1.9447,
no=2.1486
|
Crystal
Quartz
Crystal quartz is a positive uniaxial
birefrigent single crystal. We select the best
quality quartz with minimum inclusions and
refractive index variation as the raw material of
our components. Quartz is commonly used for
high damage threshold waveplates.
- Transmission range: 200 nm~2300 nm
- Thermal expansion coefficient: 7.07X10-6/K
- Density: 2.65g/cm3
|
 |
|
