Polka-Dot BeamsplittersPolka-Dot Beamsplitters

Shimadzu optical device for polychromatic light source splitting and as a substitute for monochromator sector mirrors

Polka-Dot Beamsplitters


  • Wide wavelength range from UV to IR
  • Low dependence on angle of incidence
  • Two types available: standard (to 2200 nm) and high-grade (to 3200 nm) types

Polka-Dot Beamsplitters comprise a glass substrate with an aluminum coating in a polka-dot pattern. Incident light is reflected from the coated areas but transmitted through the non-coated areas. This splitting mechanism achieves a light split ratio that is almost independent of the light angle of incidence, unlike dielectric beamsplitters.
Shimadzu Polka-Dot Beamsplitters are based on a synthetic quartz substrate that permits application across a wide wavelength range from the ultraviolet to the infrared.

Product list (table of code numbers)

Product list (table of code numbers)
  • *1: For example, "T70/R30" indicates a light ratio of 70% transmittance(T) and 30% reflectance(R).

Click to view a larger image.
Refer to Figures 1 and 2 for detailed characteristics.

Dot pattern chart

Common specifications

Specifications Nominal light ratio
T50/R50 T70/R30 T30/R70
Transmittance*2 50(+0/-5) % 70(+0/-5) % 30(+0/-5) %
Angle of Incidence 0° to 45°
Wavelength Range Standard : 250 to 2200 nm
High-grade : 250 to 3200 nm
Substrate UV Grade Fused Silica
Coating AL+MgF2
Dimension Tolerance ±0.1 mm
Clear Aperture Full surface, less outer 1.5 mm
Aperture Spacing 0.3 mm
Surface Quality 80-50 (MIL-O-13830A)
Maximum Temperature 150 °C
  • *2: At 555 nm wavelength and 0° angle of incidence
  • ※RoHS compliant (Directive 2011/65/EU + (EU)2015/863 on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment)

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