This is the SLSQ-50.8-250P, a Plano-Convex Lens with a diameter of 50.8 mm and a focal length of 250.0 mm, sourced from OptoSigma. The lens is made of fused silica, a material known for its excellent optical properties and durability.
The lens geometry is characterized by its base shape, which is circular, and its thickness. The edge thickness is 2.9 mm, while the center thickness is 5.7 mm. The effective focal length (EFL) is 250 mm, and the radius of curvature (R1) is 115 mm. The back focal length (BFL) is 246.1 mm, and the lens does not have any inner or outer radius.
The SLSQ-50.8-250P is uncoated, meaning it does not have any additional layers to enhance its optical properties. This lens is designed to work with a wavelength of 546.1 nm.
The lens is currently in stock and can be purchased directly from the vendor's website. The link to the product page is provided for your convenience.