Unpolarized beamsplitters are useful for natural, incoherent or unpolarized light. It is advised not to use these cubes in polarized optical systems.
The unpolarized beamsplitter cubes consist of a pair of precision right-angle prisms carefully cemented together to minimize wavefront distortion and beam skewing. The hypotenuse of one prism is coated with a multilayer beamsplitter coating tuned to the application. The four outside surfaces of the prism are anti-reflection (AR) coated with”V” type or broadband coatings to minimize surface reflection losses over the specific wavelength range.
For proper functioning, the incoming light should be one of the following:
– natural light
– circularly polarized
– 45° linearly polarized
This means that the s-polarized and p-polarized components should be roughly equal to each other in intensity. The outgoing beams are two partially polarized beams of approximately equal intensities.
|Range of dimensions||0.8mm-100mm|
|Range of splitting ratios||10/90 (R/T*) to 90/10 (R/T)|
|Highest accuracy of splitting ratio||±3% (single wavelength); ±5% (broadband)|
|Highest available surface figure||λ/10 (DIN: 3/0.2)|
|Highest available surface quality||20-10 S/D (DIN: 5/2×0.06)|
|Wavelength range||single wavelength or broadband|
|Highest available tolerance of beam deviation||5″ (arcsec)|
*: T=(Ts+Tp)/2, R=(Rs+Rp)/2