Beamsplitter Cube A beamsplitter cube is assembled by cementing two identical right‑angle prisms. A beamsplitter coating is deposited on the hypotenuse surface of one prism. When light strikes the coating, part of the light transmits and part reflects, splitting one beam into two. Common materials are BK7 (H‑K9L) and fused silica. Main types: NPBS (Non‑Polarizing Beamsplitter): Splits light by energy ratio (e.g.50:50), independent of polarization state. PBS (Polarizing Beamsplitter): Separates incident light into orthogonally polarized beams; P‑polarized light transmits, S‑polarized light reflects. Dichroic beamsplitter cube: Separates light according to wavelength, for color combining and multi‑spectral systems. Features: free of beam offset and astigmatism, stable for assembly. Anti‑reflection coatings are applied on four outer surfaces. Cemented cubes are not suitable for high‑power laser. Applications: interferometers, microscopes, laser systems, machine vision, optical metrology, optical communication.