These telescopes (f5 to f25) have a 7" diameter primary mirror utilizing a Cassegrain design. A beam expander (consisting of two convex mirrors) expand a femtosecond laser beam to 6". Then a 7" achromatic doublet lens collimates the light propagating into the telescope. This is a DoD design that is used both in the lab and field. The beam expander is not used in the field.