Our laser beam expanders provide a fixed expansion factor. We use either an air spaced two lens system or an achromat in order to minimize chromatic and spherical aberrations and reach diffraction limited performance. All our beam expanders have adjustable divergence. The design is Galilean, which means there is no internal focus and the system length is short compared to a Keplerian design. The lens and the mechanical parts are precisely designed to maximum pointing stability due to any rotational shifts which may occur from setup changes.

All lenses are antireflection coated for their specific wavelengths yielding transmissions over 98%. For 1064 nm the damage threshold is 5.0 J/cm² (1ns pulse at 50Hz). For 532 nm the damage threshold for expanders with fused silica on the input and optical glass on the output is 2.5 J/cm² (1ns pulse at 50Hz). For 355nm the damage threshold is 1.0 J/cm² (1ns pulse at 50Hz).