Short and long Wavelength
One of the common types of beamsplitters that is commonly used in wide variety of applications is the long and short wavelength pass filter. Basically, modified N4 stacks are what make or create an edge filter coating. These edge filters are also known as short and long wavelength filters. Now, what is the difference between the two? Usually, long wave pass filter is described as a kind of pass filter where longer wavelengths are transmitted ( at 45 degrees). On the other hand, short wave pass filter is described as a kind of filter where shorter wavelength is transmitted (at 90 degrees). But what these tow filters share in common is that they both have 50 % edge centred around 700 nm. Just like optical dichroic mirror, this coating can be beneficial to designers.
Another type of beamsplitter is plate beamsplitter. It is made up of an optical crown glasses ‘thin plate that has various kinds of coating. These types of coating are deposited on every side of the splitter. The first side of this beamsplitter is coated with a film that has divided reflection properties over the near infrared spectrum or the visible spectrum. The film coated to the first surface of the beamsplitter is considered as an all dielectric one. One of the common advantage that a designer can get from this kind of filter is that it has only low absorption. This means that in general counting, this kind of beamsplitter has 0.5% for a 50/50 splitter at 45 degrees.
As a designer, you certainly want to use a kind of beamsplitter that can provide you wide variety of benefits. If so, cube beamsplitters are the right ones for you. Basically, cube beamsplitters are rugged beamsplitters that are perfect for superposition applications of beam. This beamsplitter is also very simple and easy to mount. Another good thing about this kind of beam splitter is that the coating it has is very degradation resistant. This is possible because the coating is sea;led within the body of the cube.
In cases where there is a need for the characteristics of the polarization to be sustained in the transmitted and reflected beams, nonpolarizing plate beamspitters are the best kind of beamsplitters to use. Nenpolarizing plate beamsplitters are also used to get a 50 50 split in laser energy not considering the state of the polarization in the beam. This is what makes nonpolarizing plate unique from other kinds of beamsplitters. This is the only filter that has high polarization sensitivity.
Hybrid Partial Reflection
Another type of beamsplitter is the hybrid partial reflection coatings and this is usuaually used both for dielectrics and metals in order to generate a moderate absorption beamsplitter that has low polarization sensitivity. One of the main benefits that desigtner can get from hybrid partial redelction coating is its insensitive characteristic to change in the incidence angle. Comapred to cube beamsplitter that has the ability to cause 45 degrees of incidence angle, hybrid partial-reflection coatings has an advantage of creating such beamsplitters to be neutral in a chromatic way for divergent or convergent beams.
While there are several more types of beamsplitters such as all-doelectric nonpolarizing coating, broadband partial reflection coatings and so many more for designers, our last pick is pellicle beamsplitter. This kind of coating has a high tensile stremgth elastic membrane. Since this beamsplitter has a thin membrane, it can be advantageous over traditional plate beamsplitters. This is because problems will be virtually eliminated through negligible covering beams and very low absorption.