A classic 50:50 beam splitter will change the polarisation characteristics of incident light. Circularly-polarised laser radiation is divided into elliptically-polarised partial beams, corresponding to the different reflection values for p-polarisation and s-polarisation.
This however does not have to be the case! For CO2 lasers, we have ‘non-polarising’ beam splitters, designed to maintain the polarisation state of the laser beam for both the reflected and the transmitted partial beam. The coating is applied to laser grade ZnSe, and achieves split ratio of 50±1% at 10.6 µm, while maintaining the polarisation state of the incident light. One of the several coating layers is germanium, making the coating opaque in the visible spectrum.
Non-polarising beam splitters are suited for a laser intensity of <500 W/cm². Exceeding this may give rise to thermal lensing effects.
We have a range of standard non polarising beam splitters of diameter between 25.0 mm and 50.8 mm available for quick dispatch, as well as custom options upon request.
