Classic 50:50 beam splitters change the polarization of the incoming light. Circularly-polarized laser radiation is divided into elliptically-polarized partial beams – corresponding to the different reflection values for p-polarization and s-polarization.
However, we do it differently! For CO2 lasers, we have beam splitters available immediately that maintain the polarization state of the laser beam for both the reflected and the transmitted partial beam: We call these components “non-polarizing beam splitters.”
The coating is applied to ZnSe “laser grade” substrates at high precision:
Rs,p [10.6 µm] = 50% ±1%
The coating consists of several layers, one of which is germanium; thus, the beam splitter is impenetrable for light in the visible range.
Non-polarizing beam splitters are suited for a laser power of <500 W/cm². Higher power can produce thermal lenses.
The reason for this lies in the A absorption of the coating; for the CO2 wavelength 10.6 µm and an angle of incidence of 45°, it is equal to :
A < 1.5% ▪ AOI = 45°.
Different standard components with a diameter of between 25.0 mm and 2” are available in stock and can be provided quickly for your tests.
