Beamsplitters
Dichroic beamsplitters are longpass and shortpass filters that are generally used at 45 degree angle of incidence. They reflect one specified spectral region and transmit another. Beamsplitters are available in the visual and infrared spectrums, with reflectivity typically reaching values greater than 98% and transmission typically exceeding 85%. Dichroic beamsplitters are non-absorbing so that all light that is not transmitted is specularly reflected.
Cube beamsplitters provide highly efficient polarization of the incident beam. They also eliminate undesired ghost images of the reflected beam and the lateral displacement of the transmitted beam. Cube beamsplitters are made by coating the hypotenuse of a right angle prism and then cementing it to the hypotenuse of another right angle prism.
