SLB-30B-40N 30.0 mm Dia. x -39.7 mm FL; Double-Concave Lens Uncoated

The SLB-30B-40N is a high-quality double-concave lens offered by OptoSigma, a renowned vendor in the optical industry. This lens, designed with a base shape of a circle, is constructed from n-BK7 Schott, a popular optical glass due to its excellent optical properties.

The lens boasts a diameter of 30.0 mm and a thickness at the edge of 7.6 mm. The center thickness is significantly less at 2.0 mm, contributing to its double-concave design. The effective focal length (EFL) of this lens is -39.7 mm, indicating its diverging nature.

The first radius of curvature (R1) is -41.5 mm, while the second radius (R2) is 41.5 mm. These radii, combined with the lens's thickness, contribute to the lens's overall optical power. The back focal length (BFL) is -40.3 mm, which is the distance from the lens's rear surface to the focal point.

This lens is uncoated, meaning it does not have any anti-reflective or other coatings applied to its surfaces. While this may result in higher reflective losses, it also means the lens can be used in a wider range of applications without concerns about coating compatibility.

The lens is designed for use at a wavelength of 546.1 nm, making it suitable for a wide range of applications in the visible light spectrum. It's important to note that the lens's performance may vary at different wavelengths.