The Principle of PBS (Polarization Splitting Prism)

The principle of PBS (Polarization Splitting Prism) is based on the characteristics of polarized light. When polarized light is perpendicular to a polarizer in a particular direction, it is completely absorbed; when polarized light passes through the polarizer in that particular direction, it is completely transmitted. This direction is referred to as the transmission direction of the polarizer. The PBS uses this principle to divide polarized light into two directions, where polarized light in one direction is reflected and polarized light in the other direction is transmitted. The transmitted light and the reflected light in the strictly polarized state are linearly polarized light perpendicular to the polarization direction and parallel to the polarization direction, respectively.

A polarization splitting prism (PBS) is an optical element that divides a beam of incident light into two beams of light whose propagation directions are perpendicular to each other. There is a special relationship between the two beams of light separated by the PBS, that is, they are both linearly polarized light and the polarization directions are perpendicular to each other 2. This kind of optical element uses the nature of polarized light, so that light has different transmission or reflection characteristics in different directions, so as to realize light separation and direction control.

Polarized light is a special state of light, in which the electric vector changes regularly with time, that is, it is circular or elliptical motion trajectory on the plane perpendicular to the propagation direction, which is called circularly polarized light or elliptical polarized light. If the vibration of the electric vector of the light wave is only relatively dominant in a certain direction during propagation, this kind of polarized light is called partially polarized light. The glare formed by the smooth non-metallic surface reflected at a certain angle is polarized light, while the vibration of natural light in all directions is evenly distributed and unpolarized. Natural light can be turned into polarized light by a polarizer (polarizer), and a second polarizer (analyzer) can be used to check the polarization state of the light.

To sum up, the working principle of the PBS is based on the characteristics of polarized light. The incident light is decomposed into two beams with different vibration directions by a specific optical element, wherein the light in one direction is reflected and the light in the other direction is transmitted, so as to realize light separation and direction control. This technology has a wide range of applications in many fields such as household appliances, scientific research, and medical diagnosis.