AR-Coated WindowsWindows are frequently used in optical systems to separate the environment in one part of the system from another, such as to seal vacuum or high-pressure cells. Because the infrared transmitting material has a high index of refraction, an anti-reflection coating is typically applied to windows to minimize losses due to reflections.
For guidelines about calculating the proper thickness for a window to withstand a given pressure, see our Pressure Loading tutorial.
Below is the typical transmission of an AR coated, ZnSe window at 0° incidence:
AR-Coated Windows Graph|
Specifications
|
Standards
|
|
Dimensional Tolerance
|
Diameter: +0.000”-0.005”
Thickness: +0.005“-0.010” |
|
Edge Thickness Variation (ETV)
|
<= 3 arc minutes
|
|
Clear Aperture (polished)
|
90% of diameter
|
|
Surface Figure (power/irregularity) at 0.63µm
|
1.0 fringe/0.5 fringe
|
|
Scratch-Dig
|
20-10
|
|
AR Coating Reflectivity per Surface at 10.6µm
|
< 0.20%
|
|
|
|
|
Part #
|
Description
|
Diameter
(inches) |
Diameter
(mm) |
Thickness
(inches) |
Thickness
(mm) |
|
185217
|
ZnSe
|
0.25
|
6.35
|
0.080
|
2.03
|
|
568604
|
ZnSe
|
0.375
|
9.53
|
0.080
|
2.03
|
|
162879
|
ZnSe
|
0.50
|
12.7
|
0.080
|
2.03
|
|
457172
|
ZnSe
|
0.75
|
19.05
|
0.080
|
2.03
|
|
735199
|
ZnSe
|
1.0
|
25.4
|
0.080
|
2.03
|
|
617035
|
ZnSe
|
1.0
|
25.4
|
0.120
|
3.05
|
|
834076
|
ZnSe
|
1.1
|
27.94
|
0.120
|
3.05
|
|
184651
|
ZnSe
|
1.5
|
38.1
|
0.120
|
3.05
|
|
883636
|
ZnSe
|
2.0
|
50.8
|
0.200
|
5.08
|
|
243559
|
ZnSe
|
2.5
|
63.5
|
0.250
|
6.35
|
|
616847
|
ZnSe
|
3.0
|
76.2
|
0.250
|
6.35
|
|
AR coated windows are available in other substrates and as uncoated windows. We also offer AR coatings at other wavelengths or wavelength bands. Contact a II-VI sales representative for exact specifications.
|
|||||
|
|
|
|
|
|
|
Printer-friendly version
Send by email
