Details
Optical elements of beam expanders are made of fused silica with high LIDT coatings and provide a stable and reliable performance even using them with high power lasers.
There are two common types of fixed laser beam expanders: Keplerian and Galilean.
Basic Keplerian beam expanders are assembled using two converging lenses and benefit from real intermediate focus, where pinhole can be placed for spatial filtering, thus providing better beam wave front at the output, however the focus can cause air breakdown at high power densities.
Basic Galilean beam expanders are assembled using one diverging and one converging lenses, so there is no focal point inside the beam expander, thus it can be used for high powers. For low expansion ratios (1.3 - 20 times) the Galilean beam expander is preferred due to its simplicity and small size. We offer beam expanders made from two, three, or more spherical lens made from BK7, FS, UVFS or other glasses which suit high power applications. Beam expanders for any wavelength between 257 - 2000 nm are available on request.
