The SLB-40-70N is a Plano-Concave Lens, a type of spherical lens, sourced from OptoSigma. This lens has a base shape of a circle and is uncoated. The lens is designed with a diameter of 40.0 mm and a thickness at the edge of 8.0 mm, while the center thickness is 2.0 mm. The effective focal length (EFL) of this lens is -70.0 mm, making it a negative or diverging lens.
The lens's first radius of curvature (R1) is -36.33 mm, and the back focal length (BFL) is -71.3 mm. The lens does not have an inner or outer radius, indicating that it is a simple plano-concave lens without any additional curvatures.
The lens is made of n-BK7 Schott, a popular optical glass due to its excellent optical properties and wide transparency range. The lens is designed to work with a wavelength of 546.1 nm.
Please note that the lens is uncoated, meaning it does not have any anti-reflective or other coatings applied to it. This may affect its performance in certain applications, particularly those requiring high transmission or low reflectivity.
The lens is currently in stock and available for purchase through the provided web link.