The AL2520-C is a high-precision aspheric lens offered by Thorlabs, a leading vendor in the optical industry. This lens, designed for use with a wavelength of 780nm, boasts a diameter of 25mm and a focal length of 20mm, making it suitable for a wide range of applications.
The lens is crafted from S-LAH64, a high-quality material from Ohara, ensuring durability and reliability. It features a high numerical aperture (NA) of 0.54, which allows for a larger light-gathering capacity and improved resolution. The lens is also CNC polished, ensuring a smooth, high-quality surface finish.
The AL2520-C is coated with Thorlabs' proprietary broadband AR coating, which covers the spectrum from 1050nm to 1700nm. This coating reduces surface reflections, thereby increasing transmission and improving overall system performance.
The lens's geometry is defined by several key parameters. The inner and outer radii are both 0, indicating a circular shape. The thickness at the edge is 2.4mm, while the center thickness is 7.6mm. The lens's aspheric profile is defined by its conic constant (k1) of -1.35 and its aspheric coefficients (a2 to a16).