Beam Splitters and Windows


  • Available in 1 inch and 1.5 inch clear apertures.
  • Surface parallelism of 1 arc-second.
  • Surface quality of 80-50 or better.
  • All materials are non-hygroscopic.
  • Custom quality coatings available.
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PLX now offers the same quality beam splitters produced for our own assemblies, for use in your products.

PLX Beam Splitters are an integral part of Boresighting systems that need to manage the direction of multiple beam paths.

Offered in Zinc Selenide and Fused Silica, these optics are available in 1 and 1.5 inch clear apertures with flatness of up to λ/20, and surface parallelism of one arc-second and surface quality of 80-50 or better. All materials are non-hygroscopic. PLX Beam Splitters are uncoated. Coatings based on customer’s requirements can be designed and supplied.

Zinc Selenide

Zinc Selenide is yellow in appearance and as such is not very useful in the visible wavelengths. Its strength is in its infrared transmission, extending out to 20 microns. Zinc Selenide is chemically stable unless exposed to strong acids. It also has high resistance to thermal shock.


Spinel, also known as Magnesium Aluminate (MgAl2O4) is a transparent ceramic material. It is extremely tough making it an excellent choice for harsh environments. Spinel has transmission from the ultraviolet to the mid-infrared region (.25 – 6.5µ).

Fused Silica

Fused Silica (SiO2) benefits from a long history of being used as an excellent optical material from the ultraviolet to the mid-infrared region (0.19-3.5µ). Fused silica offers great thermal stability having one of the lowest coefficients of thermal expansion (CTE) for common optical materials. Its CTE is 0.55 ppm/K.

Material Index of Refraction Transmission Range CTE ppm/K Density g/cm3 Hardness kg/mm²
Fused Silica 1.45 0.19 - 3.5µ 0.55 2.2 500
Spinel 1.71 0.25 - 6.5µ 6.97 3.58 1650
Zinc Selenide 2.4 0.5 - 20µ 7.1 5.26 115


Cat No. CA Flatness Parallelism 3D Models
& Diagrams
BS-10-8 1 inch λ/8 5 seconds Click Here
BS-10-15 1 inch λ/15 2 seconds
BS-10-20 1 inch λ/20 1 seconds
BS-15-8 1.5 inch λ/8 5 seconds Click Here
BS-15-15 1.5 inch λ/15 2 seconds
BS-15-20 1.5 inch λ/20 1 seconds

1 Due to our continuous product improvement program, specifications are subject to change without notice.

If you don't see what you need above:
Click here for a Custom Quote, specify what your application is and our engineering staff will get back to you.