The SLB-20B-50N is a high-quality double-concave lens offered by OptoSigma, a leading vendor in the optical industry. This lens, designed with a base shape of a circle, is fabricated from the renowned material n-BK7 Schott, ensuring durability and reliability.
The lens boasts a diameter of 20.0 mm and a thickness at the edge of 3.9 mm, while the center thickness is 2 mm. The effective focal length (EFL) is -49.7 mm, indicating a strong converging power. The first radius of curvature (R1) is -51.9 mm, and the second radius (R2) is 51.9 mm, demonstrating the double-concave nature of the lens.
The back focal length (BFL) is -50.3 mm, and the lens does not have any coating, which is indicated in the 'coating' parameter being an empty object. This lens is designed to operate at a wavelength of 546.1 nm, making it suitable for various applications in the optical field.