LB11-12-30 12.7 mm Dia. N-BK7 Double-Concave Lens; EFL=-30mm Uncoated

This is a high-quality double-concave lens from CeNing Optics, featuring a 12.7 mm diameter and a center thickness of 2 mm. The lens is made of N-BK7, a popular glass type known for its excellent optical properties, particularly its low dispersion. The effective focal length (EFL) of this lens is -30 mm, making it suitable for a wide range of applications where a negative lens is required.

The lens geometry is characterized by its base shape, which is circular, and its radii of curvature. The first radius of curvature (R1) is -31.48 mm, while the second radius of curvature (R2) is 31.48 mm. These radii give the lens its double-concave shape. The inner and outer radii are both zero, indicating that the lens has a uniform thickness.

The lens is designed for use at a wavelength of 546.1 nm. It is uncoated, which means it does not have any anti-reflective coatings. This may result in some reflection at the air-glass interfaces, but it can also make the lens more cost-effective.

According to the vendor's website, this lens is in stock, making it readily available for immediate use. The website also provides further information and specifications, which can be accessed via the provided weblink.