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Beam Splitters

45°-Beamsplitter plates

DST Series

Special Properties

  • Color neutral division of light and images
  • Anti-reflection coated back side
  • Free of ghost images or phantom laser beams
  • Low loss dielectric coating design
  • Non-metallic thin film construction
  • Designed for random polarization
  • High optical quality
  • Available with large dimensions (DST500) NEW!

Typical Applications

  • Optical reference measurement systems
  • Semi-transparent optics for interferometer systems
  • Sensor technology
  • Plate beam divider for fiber applications
  • Optics for photonics research
  • Beam splitter plates in optical instruments
  • Laser beam combiner optics
  • LED-measurement technology
  • 45° beam splitter optics for laser up to medium power
  • Divider mirrors for imaging applications
  • Teleprompter mirrors


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The design and functional principle of our optical
beam splitters

The high quality optical beam splitters of the DST series split incident light into a transmission and a reflection component. Light, an image or a laser are partially reflected as by a mirror and partially transmitted as through a window. Plate beam splitters used as laser beam dividerThe input side of the 45° plate beam splitters is coated with a dielectric thin film, which determines the splitting ratio of the optics. On the back of the beam splitters there is a broadband multilayer anti-reflection coating that effectively suppresses secondary reflections. This AR-coating almost completely eliminates so-called "ghost images" and phantom laser beams in the visible wavelength range. Losses and image overlays, which would otherwise be caused by reflections from an uncoated back side are therefore virtually eliminated. Unlike dichroic beamsplitters like our SIR Hot Mirror or the SHD cold-mirrors, our DST has a non-dichroic design. Thus, it does not separate different optical spectra from each other or filter out wavelength ranges, but divides incident light rays in the VIS spectrum to a large extent color neutral.


100% dielectric coating design

A non-metallic, all dielectric structure of the thin-film layers ensures longevity and good abrasion resistance of the DST. Flat laser beam splitter opticsMoreover, the layer system of the semitransparent mirrors only has a very low absorption in the nominal wavelength range. Therefore almost no energy is lost through absorption effects, as is typical for metallic beam splitter optics. This low loss design allows the beam splitters to be used to split laser beams up to medium laser power. As substrate material for the DST splitter optics we use iron-reduced glass with excellent optical characteristics.


Polarization behavior

The polarization directions of photons in an unpolarized light beam are uniformly distributed which is not the case in a polarized light beam. All DST beam dividers are designed for unpolarized light. Therefore, when used with a polarized light or laser, the splitting ratios may deviate from the set values given in this data sheet for unpolarized light sources. The DST beam splitters are generally not specified with regard to polarization behavior or polarization effects. However, this does not exclude applications with polarized light. Often the desired splitting ratio can be easily achieved by selecting an existing higher or lower nominal splitting ratio for randomly polarized light. In such cases, the cost can be drastically reduced compared to a custom coating batch. However, if you search for specialty beam splitter optics for polarized light sources or a polarized laser, please let us know the desired specifications. In the case of special requirements for the polarization properties in most instances we are capable of fabricating customer-specific polarization-optimized beam splitter optics on a batch basis.


Customized beam splitters

In addition to our standard beam splitters, the DST300, DST500, and DST700 series, the splitting ratios can be adapted to custom specifications. From a certain quantity upwards we can also produce cube beamsplitters, beamsplitter penta-prisms, NIR dividers, and high-performance beamsplitters. Also design and manufacturing of polarizing cube beam splitters as well as of polarization obtaining cube beam splitters can be realized. Please note that such special components must always be manufactured according to customer requirements. Hence, these components cannot be listed in detail in our website. So if you search for such kind of optics, please use our inquiry form to request a quote for such specialty beam splitters.


How can I order the DST beam splitters?

We are specialized in rapid manufacturing and delivery of our beam splitters with custom dimensions. Usually we manufacture and deliver individually sized optics just as fast or even faster than stock optics with fixed dimensions can be shipped. This also and particularly applies to large production quantities. If you are in our time zone and there are no queries, you normally will receive our quotation within a few minutes. Our goal is that you exactly get the optics you need, so that the beam splitter perfectly fits into your application. You will therefore not find a shopping cart for standard products on our website.

To request a quote for one of our 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 Beamsplitters, transmittance

DST300, spectral transmittance curve

DST300 at wavelength 400-700 nm


DST500 Beamsplitters, transmittance

DST500, typical transmittance

DST500 at wavelength 400-700 nm


DST700 Beamsplitters, transmittance

DST700, typical spectral transmittance

DST700 at wavelength 400-700 nm


Product Codes

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

Substrate Materials

Coating Definitions

(Incidence angle i = 45° / random polarization)

  • Splitter ratio: R : T = 70 : 30 (± 10%)
    at wavelengths of 450-650 nm
    (Typical conditions for laser beam splitter use on request)
  • Rear side with broadband BBAR
  • Stock thickness 1,00 mm (+/-0,1)
  • Splitter ratios:
    R:T = 50:50 (± 6%) at wavelengths of 450-650 nm
    R : T = 50 : 50 (± 10%) at 430-685 nm
    (Typical ratios for laser beam splitter use on request)
  • Rear side with broadband AR
  • Standard thickness 1,00 mm (+/-0,1)
  • Splitter ratio:
    R:T = 50:50 (± 10%) at wavelengths of 450-650 nm
    (Typical ratios for laser beam splitter use on request)
  • Rear side with broadband AR-coating
  • Stock thickness 3,30 mm (+/-0,2)
  • Splitter ratios:
    R:T = 30:70 (± 8%) at wavelengths of 450-650 nm
    R:T = 30:70 (± 10%) at 400-700 nm
    (Typical ratios for laser use on request)
  • Rear side BBAR-coated
  • Stock tk. 1,00 mm (+/-0,1)


  • Depending on material, thickness, and shape
    (Flat, cube, prism, etc.)

Damage Threshold

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

Surface Quality

  • Better than 80-50 scratch & dig
  • Other per inquiry


  • up to approximately 630 mm x 810 mm (DST500)
    (Flat beam splitter optics only. Cube-, polarizing-, non-polarizing-, or prism-splitters, etc. are not feasible with such large dimensions. Please discuss the limits 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. In addition please consider our "Notes on technical specifications"