Beam splitters are special types of optical elements that split an incident laser beam into several output beams with the same characteristics. The only two characteristics that differ from the input beam are power and propagational angle. There are different types of optical beam splitters and each beam splitter type involves a unique setup and the principle of operation. Different types of beam splitters also produce different results. Let’s learn about different beam splitters and their applications.
Plate Beam Splitters
The plate beam splitter is a common beam splitter type that has significant laser applications. Plate beam splitters split an input laser beam into two distinct output beams. One output is a reflected output beam while the other is a transmitted output beam. The angle of incidence of the input beam determines the angle of propagation and direction of the output beams. Usually, the angle of propagation between two output beams is 90 degrees. The divergence and the size of the output beams do not differ from that of the input beam.
Diffractive Beam Splitters
Diffractive beam splitters are one of the most efficient and productive beam splitters. Unlike plate beam splitters that follow the principle of refraction, diffractive beam splitters work on the principle of diffraction to modify the wave nature of the input beam. While transmitting the output laser beams, diffractive beam splitters display an interference effect. Diffractive beam splitters are useful in producing beam patterns with different geometrical shapes. Therefore, we can customize diffractive beam splitters for a particular beam pattern based on the application area. We can also determine the output beam’s angular orientation and spatial separation by customizing diffractive beam splitters.
Microlens Arrays
Microlens arrays are another common beam splitter type that follows the principle of refraction like the plate beam splitter. This beam splitter has various medical and industrial applications. The setup for the Microlens array involves a series of tiny lenses (also known as lenslets). In this setup, the size and radius of curvature of every lens are the same. Microlens array splits an input laser beam into several output laser beams.
Applications
Due to excellent efficiency and productivity, diffractive beam splitters have plentiful applications in academic, industrial, and medical fields. Multi-spot diffractive beam splitters are especially efficient for aesthetic skin treatments. These beam splitters split a single input beam into an array of output beams. While converging at the focal plane, the output beams generate a unique irradiance pattern with a larger area than the affected area of the skin.
Other notable applications of diffractive beam splitters are fibre optics, laser dicing, 3D sensors, and laser scribing. Plate beam splitters also have crucial applications in fibre optics. Whereas, imaging, 3D sensing, and laser microscopy are important application areas of microlens arrays.
