87-958 50 mm Dia. Germanium Positive Meniscus Lens; EFL=50mm Uncoated

This is a 50 mm diameter Germanium positive meniscus lens, uncoated, with a focal length (EFL) of 50mm. The lens is sourced from the reputable vendor, Edmund Optics, and is currently in stock. The item data indicates that it is a spherical lens with a base shape of a circle.

The lens's geometry is intricately detailed, with a thickness of 2.6mm at the edge and 5mm at the center. The first radius of curvature (R1) is 56.64, while the second radius (R2) is 84.91. The back focal length (BFL) is 46.69. The inner and outer radii are both zero, suggesting a simple meniscus design.

The lens is made of germanium, specifically identified as "germanium burnett" in the material ID. This material is often used in infrared optics due to its high refractive index and transparency in the infrared region. The wavelength for this lens is 10600, further emphasizing its use in infrared applications.

Notably, the lens is uncoated. Coatings are often applied to lenses to enhance their performance by reducing reflections, increasing transmission, or providing other desirable optical properties. However, this lens is in its bare form, which might be suitable for specific applications where coatings are not required or preferred.