Windows
Windows are often used to create a physical barrier between two different environments – preventing two gases from mixing together, separating liquids from air, keeping a sealed system in vacuum. In many optical systems, a window is used to protect more expensive optical components (within an assembly) from back-splatter, out-gassing or other possible damage.
A window is the simplest of all optical components. While it can take nearly any form, most windows are either round or rectangular in shape. All windows are fabricated from optically transparent material, with two flat (or plano) polished surfaces.
Very often, in demanding optical applications – a window is specially fabricated with anti-reflection (AR) coatings on the external, polished flat surfaces. This AR coating improves the amount of light transmitted through the window by reducing surface losses due to reflection.
Rainbow Research Optics, Inc. manufactures and delivers precision grade and commercial quality windows from a wide range of optical materials to address applications in the ultraviolet (UV), visible, and infrared (IR) wavelength ranges. Standard optical glasses include BK 7 and synthetic fused silica, in addition to specialty optical materials like calcium fluoride (CaF2), germanium (Ge), magnesium fluoride (MgF2), silicon (Si), zinc selenide (ZnSe), and zinc sulfide (ZnS).
Window fabrication is facilitated using double-sided polishing equipment. These double-sided machines polish and finish both window surfaces simultaneously. In addition to saving labor, double-sided polishing ensures the best possible parallelism between the polished faces – often better than 1 arc sec.
So, for all of your window requirements, give Rainbow Research Optics a call to specify a custom window requirement, order a catalog window component, or discuss with our technical staff how to design the right window for your application.
Standard Windows
- Plane Windows, Wedge 3 arc min, maximum
- Parallel Windows, Wedge 10 arc sec, maximum
- Interferometer Flats, Wedge 30 degrees +/- 5 arc min
- Large Wedge Windows, Wedge 1, 2, or 3 degrees
- Square Windows
- Rectangular Windows
- Elliptical Windows
- Brewster Windows
Plane Windows, Wedge < 3 min.
Specifications:
- Substrate material: VUV MgF2, VUV CaF2, Suprasil 1, UVFS, BK7, Infrasil 301, Sapphire, IR CaF2, Silicon, Germanium, Zinc Selenide, or Zinc Sulfide
- Transmitted Wavefront: measure at 633nm
- Wedge: <3 arc min.
- Diameter Tolerance: +0.0/-0.20 mm
- Thickness Tolerance: ± 0.25 mm
- Clear Aperture: > 85% of diameter
- Chamfer: 0.3mm at 45 typical
Parallel Windows, Wedge < 10 sec.
Specifications:
- Substrate material: VUV MgF2, VUV CaF2, Suprasil 1, UVFS, BK7, Infrasil 301, Sapphire, IR CaF2, Silicon, Germanium, Zinc Selenide, or Zinc Sulfide
- Transmitted Wavefront: measure at 633nm
- Wedge: <10 arc min.
- Diameter Tolerance: +0.0/-0.20 mm
- Thickness Tolerance: ± 0.25 mm
- Clear Aperture: > 85% of diameter
- Chamfer: 0.3mm at 45 typical
Interferometer Flats, Wedge 30 ± 5 min
Specifications:
- Substrate material: Suprasil 1, UV fused silica, or BK7
- Surface Flatness: λ/10 @ 633nm
- Surface Quality: 10-5 laser quality
- Wedge: 30 ± 5 arc min.
- Diameter Tolerance: +0.0/-0.20 mm
- Thickness Tolerance: ± 0.25 mm
- Clear Aperture: > 85% of diameter
- Chamfer: 0.3mm at 45 typical
Large Wedge Windows, Wedge 1°, 2°, 3°
Specifications:
- Substrate material: UV fused silica or BK 7
- Surface Flatness: λ/10 @ 633nm
- Surface Quality: 10-5 laser quality
- Wedge: 30 ± 6 arc min.
- Diameter Tolerance: +0.0/-0.20 mm
- Thickness Tolerance: ± 0.25 mm
- Clear Aperture: > 85% of diameter
- Chamfer: 0.3mm at 45 typical
Square Windows
Specifications:
- Substrate material: UV fused silica or BK7
- Surface Flatness: measure at 633nm
- Surface Quality: 10-5 laser quality
- Wedge: <3 arc min.
- Diameter Tolerance: +0.0/-0.20 mm
- Thickness Tolerance: ± 0.25 mm
- Clear Aperture: > 85% of diameter
- Chamfer: 0.3mm at 45 typical
Rectangular Windows
Specifications:
- Substrate material: UV fused silica or BK7
- Surface Flatness: λ/10 @ 633nm
- Surface Quality: 10-5 laser quality
- Wedge: <3 arc min.
- Diameter Tolerance: +0.0/-0.20 mm
- Thickness Tolerance: ± 0.25 mm
- Clear Aperture: > 85% of diameter
- Chamfer: 0.3mm at 45 typical
Elliptical Windows
Specifications:
- Substrate material: UV fused silica or BK7
- Surface Flatness: λ/10 @ 633nm
- Surface Quality: 10-5 laser quality
- Wedge: <3 arc min.
- Diameter Tolerance: +0.0/-0.20 mm
- Thickness Tolerance: ± 0.25 mm
- Clear Aperture: > 85% of diameter
- Chamfer: 0.3mm at 45 typical
Brewster Windows
Specifications:
- Substrate material: Suprasil 1, UV fused silica
- Surface Flatness: λ/10 @ 633nm
- Surface Quality: 10-5 laser quality
- Wedge: <3 arc min.
- Diameter Tolerance: +0.0/-0.20 mm
- Thickness Tolerance: ± 0.25 mm
- Clear Aperture: > 85% of diameter
- Chamfer: 0.3mm at 45 typical
