AL2550-A 25 mm Dia. S-LAH64 High-Precision; CNC Polished Aspheric Lenses; EFL=50 mm; NA=0.23 AR 350-700nm

The AL2550-A is a high-precision aspheric lens offered by Thorlabs, a leading global manufacturer of photonics equipment. This lens is designed with a 25 mm diameter and a focal length of 50 mm, making it suitable for a wide range of optical applications.

The lens is made from n-BK7 Schott glass, a popular material due to its excellent optical properties and high damage threshold. The aspheric design of the lens helps to reduce spherical aberration, which is a common issue in traditional spherical lenses. This results in improved image quality and increased light gathering capability.

The lens features a high numerical aperture (NA) of 0.23, which allows for a wide angle of light acceptance. This is particularly beneficial in applications where a large amount of light needs to be collected or where a wide field of view is required.

The lens is coated with Thorlabs' anti-reflection coating, which is designed to reduce surface reflections and increase transmission. The coating is effective over a broad spectrum, from 350 nm to 700 nm, making it suitable for use with a wide range of light sources.

The lens is CNC polished, ensuring a high level of surface accuracy and smoothness. This is particularly important in applications where the lens is used in close proximity to the light source, as any surface irregularities can lead to a decrease in performance.