Thorlabs' Galilean type beam expanders, which are available in both fixed- and variable-magnification options, are offered for use in the UV, visible, near infrared, and mid-infrared spectral ranges. The fixed-magnification, sliding-lens beam expanders are offered with optics that have either narrowband or wideband AR coatings. Our fixed-magnification, rotating-lens optical beam expander optics have broadband AR coatings for either the VIS or NIR. Zoom beam expanders to continuously expand or reduce the diameter of a collimated beam are also available with broadband or wideband AR coatings. We also offer variable-magnification beam expanders and reflective beam expanders. These laser beam expanders can be used with CW and pulsed laser sources and incorporate large input and output apertures so as to produce diffraction-limited, expanded (or reduced) beams for a wide range of input beams.