Polarizing Beamsplitter Cube (PBS) is an optical element that separates light beams based on polarization characteristics. It is widely used in laser technology, optical instruments, precision measurement and other fields.

It is composed of two right-angle prisms bonded together by a beam splitter film, typically a multi-layer dielectric film or metal film. The incident light beam is split into two orthogonal linearly polarized light beams at the interface of the beam splitter film: s-polarized light (vertically polarized) is reflected, and p-polarized light (parallel polarized) is transmitted. 

Its application scenarios include Laser processing, Optical microscopy, Laser system