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Beamsplitter plates, DST Series

Special Properties & Features

  • Color neutral splitting of light, laser beams, and images
  • Anti-reflection coated backside
  • No double image or phantom laser beam
  • Low energy loss due to all-dielectric construction
  • Metal-free thin-film coatings
  • Designed for random polarization
  • High optical quality
  • Large dimensions possible (DST500) NEW!

Typical Applications

  • Optics in 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
  • Beamsplitter plates in optical instruments
  • Laser beam combiners
  • Measurement technology
  • Divider mirrors for imaging applications

Related optics

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

Beamsplitters split an incident light beam, a laser, or an image into a transmission and reflection component. They reflect a certain part of the incident light like an optical mirror and transmit the remaining part like an optical window.

Plate beam splitters used as laser beam divider

By applying a multi-layer dielectric thin-film coating to the input side, we determine the split ratio of our DST beamsplitters. On the reverse side, we deposit a broadband anti-reflection layer to eliminate secondary reflections. "Ghost images" and phantom laser beams that occur with beamsplitters without antireflection coating on the back are thus avoided, and energy loss caused by reflections from the back-side of the substrate is reduced to a minimum.

Unlike dichroic beamsplitters, such as our SIR filters or SHD mirrors, our DST beamsplitters work in a mostly color-neutral way. Instead of separating different light spectra from each other, they split visible wavelengths neutrally.

The non-metallic construction of our optical beamsplitters ensures excellent durability and abrasion resistance of the optics. Also, the dielectric layer system of the splitter mirrors exhibits only low optical absorption in the nominal wavelength range. So, in contrast to a metallic beamsplitter plate that usually absorbs a large portion of the incidence light, losses are small. Hence, you can also use the DST-beamsplitter plates to split laser beams with up to medium laser power. In laser applications, a part of the laser beam is mirrored by 45°, while the rest of the beam is transmitted at 0° (see figure above). This function is a typical requirement for reference measurement systems or the use in optical benches.

We designed all DST-beamsplitters for light without defined polarization, i.e., non-polarized light. When using our DST-beamsplitters with polarized light sources or with a polarized laser beam, the optical split ratio may deviate from the specifications given here, as we only specify them for random polarization. The DST beamsplitters are also undefined in terms of polarization effects. However, this does not generally exclude an optical 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 custom coating batch. If you need beamsplitter optics for polarized light or a polarized laser beam, please contact us and provide information on wavelength, split ratio, and all relevant details of your application. In the case of special optical polarization requirements, we can also manufacture polarization-optimized, customer-specific splitter optics series.

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


How can I order the DST-beamsplitters?

You won't find a shopping cart on our website because we are not limited to standard optics with fixed dimensions. We are specialized in the rapid manufacturing and delivery of our optical beamsplitters with customized sizes. 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 receive our quotation within a few minutes, provided you are in our time zone, and there are no queries.

To request a quote for our high-quality optical beamsplitters with custom dimensions, please choose a thickness from the table or click the button below.


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



DST300, spectral transmittance curve
Enlarge transmission curve of DST300

DST500, typical transmittance
Enlarge transmission curve of DST500

DST700, typical spectral transmittance
Enlarge transmission curve of DST700

Standard Thicknesses

(Please click on a glass thickness to request a quote)

Thickness (mm)


48h-Express Service
R:T = 70:30
1,00 ±0,10
R:T = 50:50
1,00 ±0,10
R:T = 50:50
3,30 ±0,20
R:T = 30:70
1,00 ±0,10
Custom thickness on request.
The thicknesses marked with "" are also available within 48–h Express Service.


  • up to approximately 630 mm x 810 mm
    (Plate beamsplitter 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.)

Split ratios for 45° angle of incidence

(All specifications are given for for random polarization)

  • R/T = 70/30 (± 10%) for 450-650 nm
  • R/T = 50/50 (± 6%) for 450-650 nm,
    R/T = 50/50 (± 10%) for 430-685 nm
  • R/T = 50/50 (± 10%) for 450-650 nm
  • R/T = 30/70 (± 8%) for 450-650 nm,
    R/T = 30/70 (± 10%) for 400-700 nm
Other ratios and incident angles are possible on demand.

Coating Construction

Substrate Materials


  • Depending on the material, thickness, and shape

Damage Threshold

  • Depending on the 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

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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