The SLB-15B-20P is a 15.0 mm diameter double-convex lens with a focal length of 20.8 mm, sourced from OptoSigma. This lens is made of n-BK7 Schott glass, a popular material for its high refractive index and low dispersion, making it ideal for a wide range of optical applications.
The lens features a base shape of a circle, with a thickness of 2 mm at the edge and 4.8 mm at the center. The effective focal length (EFL) is 20.8 mm, while the back focal length (BFL) is 19.2 mm. The radii of curvature are 20.76 mm for the first surface and -20.76 mm for the second surface, indicating a convex-convex or biconvex geometry.
Notably, this lens is uncoated, meaning it does not have any anti-reflective coatings. While this may result in higher reflective losses, it also means the lens can be used in a wider spectral range, as coatings often have specific spectral characteristics.
The lens is currently in stock and can be purchased directly from the OptoSigma website, with the provided weblink offering a direct path to the product page. This lens is a versatile option for those needing a high-quality, double-convex lens for their optical system.