BE05X-A In Stock

The ThorLabs BE05X-A is a Galilean Beam Expander designed for expanding or reducing the diameter of a collimated beam by a factor of 5x. The BE05X-A utilizes a low-aberration, achromatic design that is optimized to provide a wavefront error of less than λ/4. The design minimizes the impact on the M² value of the expanded beam, making it an excellent choice for applications that require a narrow diffraction-limited waist for use with optics or instruments that have small input apertures.

The BE05X-A uses an achromat and a lens fabricated from N-BK7 and N-BASF2. To minimize reflections at the air-to-glass interfaces, the optics used in this beam expander has a broadband anti-reflective (AR) coating of 350 nm - 650 nm deposited on both sides of each lens. The AR coatings significantly reduce the maximum reflectance per surface to less than 0.5% over the specified coating ranges compared to a typical reflectance of 4% per surface for an uncoated optic. The BE05X-A has a sliding ring design that allows for collimation to be adjusted while minimizing the beam walk-off effect inherent to lens adjustments. The red ring is used to adjust the output beam collimation, and once the desired collimation is obtained, the ring can be locked by tightening the locking screw using a 0.05" hex key.

One of the unique features of the BE05X-A is its housing design that ensures it does not rotate when turning the collimation adjustment ring, allowing the user to adjust the divergence without disturbing any attached optics and maintain pointing stability. Additionally, it has threaded input and output apertures, which allow additional lenses and filters to be installed easily along the optical axis of the beam expander. The input of this beam expander has internal SM05 (0.535"-40) and external SM1 (1.035"-40) threads for ease of use with compatible lens tubes and other optical components. Moreover, the BE05X-A has an externally M43 x 0.5-threaded output, which can be integrated with SM2 (2.035"-40) threaded components by using a compatible adapter. The Ø1.2" section of the barrel provides a smooth mounting surface with the same diameter as the compatible Ø1" lens tubes.