beam expander

A beam expander will increase the input laser beam by a specific expansion power while decreasing the divergence by the same expansion power, resulting in a smaller collimated beam at a large distance.

Beam expanders are optical systems for increasing or decreasing the diameter of a laser beam. A beam expander can enlarge an input beam by the factor M, but it can also reduce it by the factor 1/M with a reversed optical beam path. Usually beam expanders are used to increase the diameter of laser beams.

beam expander lens
laser beam expander
variable beam expander

10 Times 355nm Bex-355-10x UV Galvanometer Laser Marking Lenses Optics Beam Expander