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Beam splitter plates, DST Series

Special Properties & Features

  • Color neutral splitting of light, laser beams, and images
  • Anti-reflection coated backside
  • Free of double images or phantom laser beams
  • Low energy loss due to all-dielectric construction
  • Metal-free thin film construction
  • 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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Beamsplitters split incident light into a transmission and reflection component, so light beam, 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

We coat the input side of our DST beamsplitters with a dielectric optical thin film, which determines the splitting ratio. On the rear side, the beamsplitters feature a broadband antireflection coating that eliminates secondary reflections, so-called ghost images, or phantom laser beams. Energy losses caused by reflections from the back-side of the substrate can thus almost not occur.

Unlike dichroic beam splitters, such as our SIR filters or SHD mirrors, the DST optical splitter mirrors work in a mostly color-neutral way. They do not separate different light spectra from each other. Instead, they split incident light neutrally in the visible range.

A non-metallic construction of our optical beamsplitters ensures excellent durability and abrasion resistance of the optics. Besides, the dielectric layer system of the splitter mirrors only shows 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 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 a 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 splitting ratios 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 customer-specific coating batch. If you need beamsplitter optics 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 optical requirements regarding polarization properties, at sufficient production quantities, we can also manufacture polarization-optimized, customer-specific splitter optics.

In addition to our standard beamsplitters, the DST300, DST500, and DST700 series, we have capabilities to coat optics with splitting 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 kinds of beamsplitters are always customized and not listed 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?

There is no shopping cart on our website because we are not limited to standard optics with fixed dimensions. We are specialized in the manufacturing and delivery of our optical beamsplitters 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 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 optical beamsplitters from the DST-series with specific 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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