The LA1289-A is a high-quality plano-convex lens from Thorlabs, designed for use in a wide range of optical applications. This lens is made from N-BK7, a popular glass type known for its excellent optical properties, and is manufactured by Schott, a leading glass manufacturer.
The lens has a diameter of 0.5 inches (12.7 mm) and a focal length of 30.0 mm. The plano-convex design features a flat front surface and a curved back surface with a radius of curvature of 15.5 mm. This design results in a back focal length of 27.8 mm. The lens has a thickness of 1.8 mm at the edge and 3.2 mm at the center.
The LA1289-A is coated with Thorlabs' AR coating, which is designed to reduce reflection over the 350-700 nm wavelength range. This coating improves the lens's transmission, making it suitable for use in applications where high transmission is required.
The lens is spherical in shape, which means that its curved surfaces are parts of spheres. This shape is common in optical systems because it is relatively easy to manufacture and provides good optical performance.