AL2520-B 25 mm Dia. S-LAH64 High-Precision; CNC Polished Aspheric Lenses; EFL=20 mm; NA=0.54 AR 650-1050nm

The AL2520-B is a high-precision aspheric lens offered by Thorlabs, designed with a 25 mm diameter and a focal length of 20 mm. This lens is crafted from S-LAH64, a high-quality optical glass from Ohara, ensuring excellent optical performance. The lens's aspheric design helps minimize spherical aberration, providing superior image quality.

The lens features a high numerical aperture (NA) of 0.54, which allows for a wide angle of light acceptance and increased light-gathering capability. This makes the AL2520-B suitable for applications that require high light transmission and resolution, such as microscopy, beam shaping, and laser applications.

The lens is coated with Thorlabs' BBAR (Broadband Anti-Reflection) coating on both the front and back surfaces, reducing reflection losses across the 650-1050 nm spectral range. This coating enhances the lens's transmission efficiency, making it an ideal choice for near-infrared (NIR) applications.

The lens's geometry includes a 2.4 mm thickness at the edge and a 7.6 mm thickness at the center, providing structural rigidity while maintaining a low profile. The lens's inner and outer radii are 0 mm, indicating a circular shape that allows for versatile mounting and integration into various optical systems.