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Optical Beamsplitters

Beamsplitter plates, DST-Series

Special Characteristics

  • Low-loss dielectric layer design
  • Made for random polarized light
  • Rear side antireflection coated
  • Largely color neutral
  • Strong suppression of ghost images
  • High optical quality
  • Non-metallic thin film cotings
  • Designed for 45° incident angle use
  • Large dimensions available (DST500)

Typical Applications

  • Efficient division of light, images and laser beams
  • Reference measurement systems
  • Plate beamsplitters for lasers
  • Fiber optical beamsplitters
  • Interferometer optics
  • Laser beamsplitters
    (up to medium laser powers)
  • Sensor technology
  • Teleprompter mirrors
  • Laser beam combiners
  • Semi-transparent mirror optics

How our plate beamsplitters work

Our beamsplitters are used in optical systems to split a incident light beam in two separate light beams. To achieve this, the input surface Plate beamsplitters used as laser beam dividerof each beamsplitter is vacuum coated with a dielectric, partially permeable optical thin film coating. The rear side of the beamsplitters has a broadband anti–reflection coating in order minimize undesired secondary reflections from the backside of the glass substrate. This effectively prevents ghost images or interfering double beams as well as optical surface reflection losses, which otherwise would occur from an uncoated back side of the glass substrate. All of our plate beamsplitters are designed for a well-defined dividing ratio (R : T) for visible, random polarized light and at an angle of incidence of 45°.

Optical design and special properties

Unlike a dichroic splitter, our DST precision splitter is designed to be largely color neutral over the full optical operating wavelength spectrum. Due to the metal-free construction, our beamsplitter coatings offer a higher scratch resistance and better durability than most metal based beamsplitters. Moreover, the vacuum coated, non-metallic, dielectric, optical multi-layer coating system, offers a very low Flat laser beam dividing opticsabsorption in the visible range, which keeps the loss of light energy negligible. The average optical energy absorption of our beamsplitters in the nominal wavelength range typically is less than 1 %. This is a considerable improvement over metal based beamsplitters, which often absorb a large portion of the incident energy. Hence, this efficient 100 % dielectric coating design makes our beamsplitters ideal for the division of laser beams up to medium laser powers. The laser beam power they can withstand, depends on the laser beam diameter and therefore on the power density of the laser beam used. Because our DST-series are designed to split light with random polarization, the splitting ratio for light and laser applications with polarization might deviate from the ratios shown in this data-sheet, which are all defined for unpolarized light. Also, we do not make statements about polarization effects that may occur with our DST plate beamsplitters when used with a polarized laser beam or with polarizing light sources. In cases you need a specific model for polarized light or if you need a polarization optimized laser beamsplitter optics, we of course can create a customized solution for you, based on your exacting optical polarization requirements. Please consider, that such custom designed optical beamsplitters require to be manufactured at a reasonable production quantity and that a single piece production of a complex, customized optical coating can be very uneconomical to make.

Standard beamsplitters and customized beamsplitters

In addition to our standard beamsplitters, which are available from stock, the light division ratios of all of our beamsplitter optics can be customized based on a full coating-run. At adequate quantities, we can also manufacture optical cube -, high power laser beam-, polarizing-, dichroic cube-, near infrared beamsplitters as well as beamsplitter prisms. This kind of optical components are custom-made and are therefore only possible on request. Please use our inquiry-form for custom optics, to request a quotation for a batch of your customized, high precision, optical cube beamsplitters or for your beamsplitter prism. If you need engineering support for the optical design or in case you are looking for further information, please do not hesitate to contact our staff.

How can I purchase the standard DST beamsplitters?

We are not confined to a few stock sizes like it is often the case for resellers without an in-house manufacturing. This is why you will not find a shopping cart on our website. We are well organized and specialized in the quick manufacturing of our standard beamsplitters at customized dimensions. In many cases, we can supply customized dimensions as fast or even faster than the competition can supply stock items, and this even at large production quantities. To request a quotation for one of our DST beamsplitters, please click on the button below, which will forward you to our inquiry form:

Request for Quotation

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DST300, optical transmittance
DST300 Beamsplitters, spectral transmittance curve 
DST300 beamsplitters at wavelength 400-700 nm

DST500, optical transmission
DST500 Beamsplitters, typical transmittance curve
DST500 beamsplitters at wavelength 400-700 nm

DST700, optical transmission
DST700 Beamsplitters, typical spectral transmittance
DST700 beamsplitters at wavelength 400-700 nm


Product Codes

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

Substrate Materials

Coating Definitions

(All for an incidence angle of i=45°, random polarization)

DST300 beamsplitters
  • R : T = 70 : 30 (± 10 %) at wavelengths
    of 450-650 nm
    (Typical ratio for laser beam use on request)
  • Rear side with vacuum broadband AR coating
  • Stock thickness 1,00 mm (+/-0,1)
DST500 beamsplitters
  • R : T = 50 : 50 (± 6 %) at wavelengths
    of 450-650 nm
  • R : T = 50 : 50 (± 10 %) at 430-685 nm
    (Typical ratio for laser beam use on request)
  • Rear side vacuum broadband AR coated
  • Standard thickness 1,00 mm (+/-0,1)
DST500T beamsplitters
  • R : T = 50 : 50 (± 10 %) at wavelengths
    of 450-650 nm
  • R : T = 50 : 50 (± 10 %) at 430-700 nm
    (Typical ratio for laser beam use on request)
  • Rear side vacuum broadband AR coated
  • Stock thickness 3,30 mm (+/-0,2)
DST700 beamsplitters
  • R : T = 30 : 70 (± 8 %) at wavelengths
    of 450-650 nm
  • R : T = 30 : 70 (± 10 %) at 400-700 nm
    (Typical ratio for laser beam use on request)
  • Rear side with vacuum broadband AR coating
  • Stock tk. 1,00 mm (+/-0,1)


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

Damage Threshold (laser applications)

  • Depending on laser beam diameter and laser power (Please send a request for information)

Surface Quality

  • Typically better than 80-50 scratch & dig
  • Other on request


  • up to approximately 630 mm x 810 mm
    (flat beamsplitters only. Cube- or polarizing- beamsplitters etc. are not possible at this size. Please discuss the limits for cube- or polarizing- beamsplitters 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"