The AL2520M-A is a high-precision aspheric lens offered by Thorlabs, a leading vendor in the optical industry. This lens is characterized by its 25 mm diameter and is designed for use with a wavelength of 780 nm. The lens is made from S-LAH64, a high-quality optical material from Ohara, ensuring excellent optical performance.
The lens features an effective focal length (EFL) of 20 mm, making it suitable for a wide range of optical applications. It has a high numerical aperture (NA) of 0.54, which allows for a larger light-gathering capacity and improved resolution. The lens is also coated with an anti-reflective (AR) coating, specifically designed for the 350-700 nm range, which reduces surface reflections and increases transmission.
The AL2520M-A lens is CNC polished, ensuring a high level of precision and surface quality. The geometry of the lens includes a center thickness of 7.6 mm and an edge thickness of 2.4 mm, providing robustness and durability. The lens also features a front aspheric surface with a conic constant of -1.35 and high-order aspheric coefficients up to the 16th order.