Beam on coated components picture
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Beam Splitters

Beamsplitter plates, DST Series

Special Properties & Features

  • Color neutral splitting of light, laser beams and images
  • Anti-reflection coated back side
  • Free of double images or phantom laser beams
  • Low energy loss due to dielectric coating
  • Metal-free thin film construction
  • Designed for random polarization
  • High optical quality
  • Available with very large dimensions (DST500) NEW!

Typical Applications

  • Optical reference measurement systems
  • Laser beamsplitters in optical benches
  • Semi-transparent mirrors for interferometer systems
  • Division or merging of beam paths
  • Sensor technology
  • Fiber optical applications
  • Image processing
  • Machine vision
  • Photonics research
  • Beam splitter plates in optical instruments
  • Laser beam combiners
  • Measurement technology
  • Divider mirrors for imaging applications

Related optics

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Beam splitters split an incident light beam into a transmission and a reflection component. Light, a laser, or an image are partially reflected, as through an optical mirror, and partially transmitted, as through an optical window.

Plate beam splitters used as laser-beam divider

The input side of our DST beam splitter plates is coated with a dielectric thin film coating which determines the splitting ratio. On the rear side, the beam splitters feature a broadband antireflection coating which almost completely eliminates secondary reflections, so-called ghost images or phantom laser beams. Energy losses caused by reflections from the rear substrate surface can thus almost not occur. Unlike dichroic beam splitters, such as our SIR filters or SHD mirrors, DST optical splitter mirrors do not work like dichroic optics. They do not split different light spectra from each other. Instead they divide an incident light beam in the visible range in a largely color-neutral way. A non-metallic construction of our beam splitters ensures excellent durability and abrasion resistance. Besides, the dielectric layer system of the splitter mirrors only has a very low absorption in the nominal wavelength range. So, in contrast to a metallic beam splitter plate that usually shows a high absorption, only a very small amount of light gets lost. Hence, the DST-beam splitter plates can also be used as beam splitters for laser beams with up to medium laser power. In this application, a part of the laser beam is mirrored by 45°, while the rest of the beam is transmitted at 0° (see picture above). This function is often required in optical benches and reference measurement systems.

All DST beam splitters are designed for light without defined polarization, i.e. non-polarized light. When using DST beam splitters with polarized light sources or with a polarized laser beam, the optical splitting ratios may deviate from the specifications given here, as they are specified for randomly polarized light. The DST beams splitters are undefined in terms of polarization or polarization effects. However, this does not generally exclude an application with polarized light sources. Often the desired gradation can be achieved by selecting a higher or lower existing ratio and the cost can be drastically reduced compared to a customer-specific coating batch. If you need a beam splitter plate for polarized light or a polarized laser beam, please contact us with information on wavelength, splitting ratio and all relevant details of your application. In case of special requirements regarding polarization properties, at sufficient production quantities we can also manufacture polarization-optimized, customer-specific divider optics.

In addition to our standard beam splitters, the DST300, DST500, and DST700 series, we have capabilities to coat splitting ratios according to custom specifications. Also feasible on a batch basis are polarizing beamsplitter cubes, beam splitter prisms, near-infrared beam splitters, and high-power beam splitters. Design and production of polarizing beamsplitter cubes, as well as polarization direction maintaining optics can also be realized. Such beam splitter components are always customized and therefore not listed in detail on our website. Please use our inquiry form to request customized beam splitter optics, technical assistance, and further information.


How can I order the DST-beamsplitters?

You will not find a shopping cart on our website, because we are not limited to standard items with fixed dimensions. We are specialized in manufacturing and delivering our DST beam splitters with customized sizes very quickly. Therefore, we often ship tailor-made beamsplitters just as fast or even faster than stock items are shipped usually. Moreover, this also applies to large production quantities! As a rule, you will receive our quotation within a few minutes, provided you are in our time zone and there are no queries.

To request a quote for one of our high-quality DST beam splitters with individual dimensions, please click on the button below:


Request for Quotation

48h-Express Service Also available in 48 h Express-Service



DST300 transmittance

DST300, spectral transmittance curve

DST300 at wavelength 400-700 nm


DST500 transmittance

DST500, typical transmittance

DST500 at wavelength 400-700 nm


DST700 transmittance

DST700, typical spectral transmittance

DST700 at wavelength 400-700 nm


Product Codes

(Reflection (R) : transmission (T), defined for unpolarized light)
  • DST300 (R : T = 70 : 30)
  • DST500 (R : T = 50 : 50)
  • DST700 (R : T = 30 : 70)
  • Other ratios and incident angles are possible on demand

Substrate Materials

Coating Definitions

(All specifications are given for an incidence angle of 45° and for random polarization)

  • R:T = 50 : 50 (± 6%) for 450-650 nm
    R:T = 50 : 50 (± 10%) for 430-685 nm
  • Backside with broadband AR-coating
  • Stock thickness 1,00 mm (+/-0,1)
  • R:T = 30 : 70 (± 8%) for 450-650 nm
    R:T = 30 : 70 (± 10%) for 400-700 nm
  • Backside BBAR-coated
  • Stock thickness 1,00 mm (+/-0,1)


  • Depending on the material, thickness, and shape

Damage Threshold

  • Depending on laser beam diameter and power
    (Please send an inquiry if relevant)

Surface Quality

  • Better than 80-50 scratch & dig (MIL-0-13830A)
  • Different surface qualities per inquiry


  • up to approximately 630 mm x 810 mm (DST500)
    (Plate beam splitter optics only. Cube-, polarizing-, non-polarizing- beamsplitters, beamsplitter-prims, and comparable components are not feasible with such large dimensions. Please discuss the size limitations with our engineers.)

Other Specifications

  • Adherence according to MIL-C-675 C (tape test)
  • Abrasion-resistance referred to MIL-M-13508 C
All given details and specifications are mean reference values and are not guaranteed. Also, please consider our "Notes on technical specifications".

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