The 69-638 is a 25mm diameter, 30mm focal length Plano-Convex lens, sourced from Edmund Optics. This lens is made of Germanium burnett, a material with a refractive index suitable for infrared applications, particularly at a wavelength of 10600nm.
The lens's geometry is characterized by a 2.13mm edge thickness and a 3mm center thickness, with a 90.12mm radius of curvature on the convex side. The effective focal length (EFL) is 30mm, and the back focal length (BFL) is 29.25mm. The lens has no coating, which means it does not have any anti-reflective or protective layers.
This lens is a Spherical lens, which means it has a spherical surface - a surface shaped like a piece of a sphere - on both sides. The Base Shape is Circular, indicating that the lens has a circular cross-section.
The lens's information status is "Valid - in stock", according to the vendor's website, indicating that it is readily available for purchase and use.