This item is a double-convex lens, type BICX-25.4/411.5C, with a diameter of 25.4 mm and a focal length of 400 mm. The lens is sourced from Laser Components, a reputable vendor in the optical industry.
The lens is spherical in shape, specifically designed with a base shape of a circle. It is manufactured from the material n-bk7 schott, a common choice for its excellent optical properties.
The geometry of the lens includes a thickness of 2 mm at the edge and 2.4 mm at the center. The radii of curvature are 411.5 mm for the first surface and -411.5 mm for the second surface, indicating a double-convex design. The lens does not have any coating, as indicated by the empty "coating" field in the item data.
The lens is designed to operate at a wavelength of 633 nm. The item data also indicates that this lens is in stock and available for immediate purchase. Further information and specifications can be found in the datasheet provided by the vendor, accessible via the provided weblink.