Beam-Splitter (BS) is a term used to describe various coatings which divide a beam of light into separate beams. Dichroic filters, covered in our Color Filter section, are often called beam-splitters. However, in this section, we will be speaking specifically about beam-splitters that divide light at each wavelength of interest into the two separate beams with an incident angle around 45 degrees from normal.

Dielectric coatings, however, have the advantage of being non-absorbing and so allow for greater throughput of energy. For example, a dielectric coating can be used for a 50/50 beam-splitter coating. Inconel, on the other hand, can yield approximately 30% transmission and 30% reflection due to the absorption inherent in the metal film. Standard dielectric beam-splitter coatings include 30/70, 50/50, and 70/30. However, we would welcome any custom requirements you may have. Please feel free to contact us with your specifications.

Partially transmitting metals make very useful beam-splitter coatings. Two common metals used for this purpose are Inconel and chrome. Metal beamsplitters are often very broad and can cover a much wider spectrum of wavelengths than their dielectric counterparts.

	45-degree Plate Beamsplitter 30%R, 70%T This coating transmits 70% and reflects 30% (+/-10 %) from 450-650 nm at 45 degrees angle of incidence
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	45 degree Plate Beamsplitter 50%R, 50%T This coating is designed to transmit 50% and reflect 50% (+/-10%) from 425-650 nm at 45 degrees angle of incidence. May be applied to a flat plate or to the diagonal surface of a cube made from two right-angle prisms cemented together
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	45-degree Plate Beamsplitter 70%R, 30%T This coating reflects 70% and transmits 30% (+/-10%) from 450-650 nm at 45 degrees angle of incidence
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