Beam expander housing is a crucial component in optical systems, particularly in applications involving lasers and other collimated light sources. It serves as the protective and structural enclosure for the optical elements that comprise a beam expander, which is a device used to increase the diameter of a laser beam while maintaining its collimation.

The primary function of the beam expander housing is to provide a stable and precise alignment of the optical elements, such as lenses or mirrors, that make up the beam expander. This ensures that the expanded beam maintains its desired properties, such as uniformity and low divergence.