Common Beam Expander Features

• Ideal for reducing beam divergence
• Compatible with many of our standard optic for focusing
• Diffraction limited performance with <λ/4 wavefront error introduced
• Input aperture is threaded to work with our SM05 and SM1 threaded adapters
• Easy to mount and align using our standard posts and mounts

These Galilean Beam Expanders provide an ideal solution for expanding or reducing beam diameters. Beam expanders are commonly used to reduce divergence. Another common use is to expand the beam and then focus with another lens to take advantage of a reduction in spot size. These beam expanders have all been designed to minimize the telescope length, minimize the introduced wavefront error (<λ/4) and provide diffraction limited performance (for <Ø1mm input).
The design incorporates a plano-concave singlet to provide the desired divergence and a doublet which has been computer optimized to balance aberrations and re-collimate the beam. The rotary barrel controls adjustment of the diverging lens with graduations in 50µm increments. All of the designs are available in A (350-650nm), B (650-1050nm) and C (1050-1620nm) broadband anti-reflection coated versions.

New Improved Design!

The new BE series beam expanders now come with an improved design for easier mounting and alignment (see application idea below). The input aperture has been threaded to work with our SM05 (for BE02 to BE05 models) and SM1 (for BE10 to BE20 models). This allows for using standard ThorLabs SM series of adapters, lens holders, iris diaphragms etc.

The right image shows the beam expander mounted in a KS1 lens mount. All BE series beam expander has been notched to mount in KS1 kinematic mount (for BE02 to BE05 models) or KS2 kinematic mount (for BE10 to BE20 models).

The image to the left shows the new mounting configuration available with all BE series beam expanders. 4-40 (for BE02 to BE05 models) or a 8-32 (for BE10 to BE20 models) tapped hole allow for an alternate mounting style.