AL2550M-C 25 mm Dia. N-BK7 High-Precision; CNC Polished Aspheric Lenses; EFL=50 mm; NA=0.23 AR 1050-1700nm

The AL2550M-C is a high-precision asperic lens offered by Thorlabs, a leading global manufacturer of photonics equipment. This lens boasts a 25 mm diameter and is crafted from N-BK7, a popular glass type known for its excellent optical properties. The lens is designed for use at a wavelength of 780 nm.

The lens's geometry is defined by its inner radius of 0 mm, outer radius of 0 mm, and a thickness of 3 mm at the edge. The effective focal length (EFL) is 50 mm, and the lens has a front radius of curvature (R1) of 25.56 mm and a back radius of curvature (R2) of 0 mm. The center thickness is 6 mm, and the lens's conic constant (k1) is -1.01.

The lens's aspheric front surface is defined by high-order aspheric coefficients up to the 10th order, ensuring superior image quality and minimal spherical aberration. The front and back surfaces are coated with a broadband anti-reflective coating (AR) that is effective between 1050 nm and 1700 nm, further enhancing the lens's performance.

The lens's numerical aperture (NA) is 0.23, indicating a wide acceptance angle and high light-gathering capability. This makes the AL2550M-C suitable for a wide range of applications, including imaging, beam shaping, and laser systems.