This is a high-quality Double-Concave Lens, offered by Laser Components, with a diameter of 19.1 mm and a focal length of -20 mm. The lens is designed for use in the ultraviolet spectrum, specifically at a wavelength of 248 nm.
The lens is made of fused sil mal-1965, a material known for its excellent optical properties and durability. The base shape of the lens is circular, and it features a spherical geometry. The inner radius of the lens is 0, while the outer radius is also 0, indicating a symmetrical design.
The lens has a thickness of 6.6 mm at the edge and 2 mm at the center. This asymmetry in thickness is common in lenses designed for specific focal lengths and wavelengths. The lens is uncoated, which means it does not have any additional layers to enhance its optical properties or protect it from environmental factors.
The lens is currently in stock and available for immediate purchase. More detailed information about the lens, including its specifications and performance characteristics, can be found in the datasheet provided by Laser Components.