The 112-0409E is a plano-concave lens with a diameter of 38.1 mm and a focal length of -100 mm, sourced from EKSMA Optics. This lens is a spherical type, featuring a base shape of a circle. The lens's geometry includes a thickness edge of 5.5 mm and a thickness center of 2 mm. The inner and outer radii are both zero, indicating a plano surface on one side and a concave surface on the other.
The lens is made of n-BK7 Schott material, a popular choice for its high refractive index and low dispersion. It is designed to operate at a wavelength of 546 nm. The lens does not come with any coating, which means it is uncoated. This could lead to higher levels of reflection and lower transmission compared to coated lenses. However, uncoated lenses are often more cost-effective and can be suitable for certain applications.
Please note that the weblink provided leads to the EKSMA Optics' page for plano-concave lenses, where you can find more information about this product and its availability.