Beam splitter / splitter mirror

Beam splitters are optical splitter mirrors in which a defined part of the light is transmitted and the other part is reflected. This is often 50% each, but all other distributions are also possible.

The beam splitter does not heat up nor emits any heat. So, virtually no light is "lost".

This requires the use of high-purity glass, which is why Prinz Optics primarily uses Borofloat.

The picture clearly shows the outstanding colour uniformity in transmission and reflection of the AT60 beam splitter.

This optical filter - beam splitter AT 40 is used for colour-neutral light attenuation.

Glass types and sizes

The beam splitters are offered in the following materials / thicknesses / sizes

In addition, we also provide even smaller filter sizes with less material thickness. We can cut the filters round as well as in any other shape – please see Customised Glass Cutting Service.

All technical data can be found here:


Standard glass thicknesses

Float glass2 mm3 mm4 mm5 mm6 mm
Borofloat1.1 mm2 mm3.3 mm5.5 mm6.5 mm
Clear glass2 mm3 mm4 mm5 mm6 mm

Standard sizes

minimumin mm range depending on material
maximumgross 1,150 x 850 mm / net 1,080 x 800 mm


Spectral curve FE Red


Beam splitters / Splitter mirrors for flight simulators and teleprompters

For applications in road and flight simulators and teleprompters, light needs to be split into transmission and reflection as colour neutral (achromatic). To prevent double images, the reverse side is anti-reflective.

Our standard beam splitters for flight simulators and teleprompters

Filter typesTransmissionReflec­tion 

Beam splitters for lighting systems

Our AT40 filters are particularly suitable for colour-neutral light attenuation (without anti-reflection coating on the back).

Beam splitters for lighting systems

Filter typesTransmissionReflec­tion 

An overview of all our optical filters for industry can be found here

All filters for industry 


Whitepaper optical filters


Whitepaper glass coatings


Our consulting service

As a customer-focused manufacturer, we are here to support with advice and measures that will help bring your projects to life.