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Optical Beam Splitters

Beam splitter plates, DST-Series

Special Characteristics

  • Low-loss dielectric layers
  • Made for random polarized light
  • Rear side antireflection coated
  • Neutral in color
  • Strong suppression of ghost images
  • High optical quality coating
  • Not dichroic
  • Non-metallic construction
  • Designed for 45° incident angle use

Typical Applications

  • Efficient division of light, images and laser beams
  • Reference measurement applications
  • Beam splitter plates
  • Fiber optical beamsplitter
  • Interferometer optics
  • Laser beamsplitter (up to medium power beams)
  • Sensor technology
  • Teleprompter mirrors
  • Beam combiner
  • Semi-transparent mirrors

How our plate beam splitters work

Our beam splitter optics are used to divide an incident light beam in two separate beams. To achieve this, the input surface Plate beam splitters used as laser beam dividerof each beam splitter is vacuum deposited with a dielectric, partially transmitting optical thin film coating. The rear side of each beam splitter has a broadband anti–reflection coating in order minimize the undesired secondary light reflection from the backside of the glass substrate. This effectively prevents ghost imaging and surface reflection losses, which otherwise would occur from an uncoated back side of the substrate. All of our optical beam splitter plates are designed for a well defined dividing ratio (R:T) for visible light and at an angle of incidence of 45°.

Construction and special properties

Unlike dichroic beamsplitters, our DST precision beam splitters are designed to maintain neutral in color over the full operating wavelength range. Due to the metal-free construction, the beamsplitter coatings offer a high mechanical stability and good durability. Moreover, the vacuum deposited, non-metallic, dielectric multi-layer optical coating system, shows a very low Flat laser beam splitterabsorption in the visible range, which keeps the loss of light energy negligible. The average optical energy absorption of our beam splitters in the nominal wavelength range typically is < 1%. This is a considerable improvement over metal based beamsplitter coatings, which often absorb a large portion of the incident light energy. This efficient dielectric design makes the DST beamsplitter coatings ideal to be used to split laser beams of up to medium laser powers. The laser beam power they can withstand, depends on the application and the power density of the laser and also on the laser beam diameter. 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 given for unpolarized light. Hence, we don't make any calls on polarizing or polarization effects that might occur from our DST beam splitter plates when used with polarized lasers or light sources. Nevertheless, if you need a specific model for polarized light or if you need a polarization optimized laser beam splitter, we can create a customized solution for you, based on your exact optical polarization requirements. Please consider that such custom designed optical beam splitters require to manufacture a reasonable quantity and that a single piece production of such a complex customized optical device is very uneconomical to make.

Standards and customization

In addition to our standard dielectric optical beam splitter plates which are available from stock, the light division ratios of all of our beam splitter optics can be customized on a per batch basis. At adequate quantities, we also manufacture optical cube -, high power laser-, polarizing-, dichroic cube-, near infrared beam splitters and beam splitter prism optics. Those optics are all custom made and are therefore only possible per inquiry. Please use our custom optics inquiry form to request a quotation for a batch of your customized high precision optical beam splitter cube or beam splitter prism. If you need support in the optical design or if you need further information, please do not hesitate to contact us.

How to purchase our standard beamsplitters

We are not confined to a few stock sizes, like it is often the case for reselling companies 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 manufacturing of custom dimensions of any of our standard beam splitters very quickly. 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. In order to request a quotation and pricing for any of our DST- beam splitters at custom sizes or customized shapes, please click the button below to be redirected our inquiry form:

Request for Quotation

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Specifications of our DST standard
Beam Splitter Plates

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

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

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


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 beamsplitter
  • R:T = 70:30 (±10%) at wavelengths of 450-650nm
  • Rear side with vacuum broadband AR coating
  • Stock thickness 1,0mm (+/-0,1)
DST500 beamsplitter
  • R:T = 50:50 (±6%) at wavelengths 450-650nm
  • R:T = 50:50 (±10%) at 430-685nm
  • Rear side vacuum broadband AR coated
  • Standard thickness 1,0mm (+/-0,1)
DST500T beamsplitter
  • R:T = 50:50 (±10%) at wavelengths 450-650nm
  • R:T = 50:50 (±10%) at 430-700nm
  • Rear side vacuum broadband AR coated
  • Stock thickness 3,3mm (+/-0,2)
DST700 beamsplitter
  • R:T = 30:70 (±8%) at wavelengths of 450-650nm
  • R:T = 30:70 (±10%) at 400-700nm
  • Rear side with vacuum broadband AR coating
  • Stock tk. 1,0mm (+/-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 contact us for details)

Surface Quality

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


  • up to approximately 630mm x 810mm
    (flat beam splitters only, no cube, prisms etc. at this size)

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"