Optical beam-splitter
II-VI INFRARED
Beamsplitters are used to reflect a certain percentage of incident energy, while transmitting the remaining energy. In most cases, beamsplitters are angle, wavelength, and polarization sensitive.
Most beamsplitter coatings are highly polarization sensitive. Thus, if the source’s polarization state varies with time, as in some randomly polarized lasers, the beamsplitters transmission will also vary with time.
The beamsplitters described here are designed for use at 45° angle of incidence and 10.6µm wavelength. At this angle of incidence, there can be significant differences in the transmittance/reflectance values for s and p-polarizations. It is essential that the laser’s polarization state be specified when ordering these optics. (See our Polarization tutorial for definitions of s and p polarizations.)
Our standard beamsplitter is supplied with a wedge of 6 to 10 arc minutes. This wedge amount significantly reduces interference caused by reflections off the second surface, which can cause an etalon effect and disturb optical performance. All II-VI beamsplitters are E-field optimized to minimize absorption and increase their damage threshold.
