A beam splitter is an optical component used to split an input beam of light into two parts. It is a common part of optical devices such as laser or illumination systems. Their use is also favored for fluorescence applications, optical interferometry, or life science or semiconductor instrumentation. The incoming light is split based on its overall intensity, wavelength, or even polarization.
Types of beam splitter
These days a beam splitter can be acquired in the plate, cube, pellicle, polka dot, or specialty prism shape. These forms are used in a variety of coatings or substrates for their anti-reflective properties. The standard type of splitter can split inbound light by a specific ratio, which does not depend on wavelength or polarization state. This is found to be ideal for one way mirrors, and illumination sub systems.
Another type is the Dichroic splitters, which cut off part of the wavelength and so find use in the construction of laser beam combiners, among other things. Non-Polarizing beam splitters are even better for manipulating laser beams, and split the light based on overall intensity. The Polarizing type is effective in the area of photonics instrumentation.
Polarizing Beam splitters
These are used to split un-polarized light into its polarized components. This has nothing to do with the wavelength or intensity. Such a beam splitter is used in semi-conductors to transmit p-polarized light and push back s-polarized light. Polarizing splitters can be designed for a 0° or 45° angle of incidence, where the split beams come out at right angles to each other, based on the configuration.
It is possible to get a beam splitter made from a range of configurations these days. Plate beam splitters, for instance, come in many sizes, each optimized for performance inside a specific spectral band. Cube beam splitters, meanwhile, are good for applications which require durability, or simplified mounting, or integration within an optical system. The lateral displacement type of splitter is made to function with common laser wavelengths and ranges.
That was some basic information on beam splitters. As mentioned above, they are used as optical glass coating for various applications, based on the requirements of the buyer. One example are Dichroic optical coatings, which divide the light beam into a number of spectrally distinct beams. In any case, it is important to choose the right coating based on the wavelengths you need it to perform at, and intended polarization ratio for the split beams.