68-242 25mm Dia. Germanium Infrared Aspheric Lens; EFL=75mm; NA=0.17 Uncoated

This is a 25mm diameter Germanium Aspheric Lens, catalog number 68-242, sourced from the renowned optical vendor, Edmund Optics. The lens is designed for infrared applications with a wavelength of 4000nm. It boasts an effective focal length (EFL) of 75mm and a numerical aperture (NA) of 0.17, making it suitable for a range of optical systems.

The lens geometry is intricately designed with an inner radius of 0mm, an outer radius of 0mm, and a center thickness of 2.8mm. The edge thickness is 2.39mm, providing robustness and durability. The aspheric design, characterized by radii of curvature r1=59.61mm and r2=78mm, ensures high-quality imaging with minimal spherical aberration. The back focal length (BFL) is 72.3mm, which is crucial for determining the lens's position in an optical system.

Notably, the lens is uncoated, which means it does not have any anti-reflective or other coatings. While this may result in higher reflective losses, it also means that the lens is less susceptible to damage from environmental factors or handling.

The lens's specifications are currently valid and in stock, according to the vendor's website. For more detailed information or to make a purchase, users can follow the provided weblink.