The SLSQ-20-40N is a Plano-Concave Lens, a type of spherical lens, sourced from OptoSigma. This lens is designed with a base shape of a circle and is uncoated. The lens is fabricated from fused silica, a material known for its high transparency and resistance to thermal shock.
The lens has a diameter of 20.0 mm and a thickness at the edge of 5.0 mm. The center thickness is 2.0 mm. The effective focal length (EFL) of this lens is -40.0 mm, indicating that it is a diverging lens. The radius of curvature (R1) is -18.4 mm, and the back focal length (BFL) is -41.4 mm. The lens does not have an inner or outer radius.
The lens is designed to operate at a wavelength of 546.1 nm. It is important to note that the lens does not come with any coating, which may affect its performance in certain applications.