The 47-908 is a Plano-Concave Lens with a 20mm diameter and a -30 FL (focal length) from Edmund Optics. This lens is designed for use within the visible light spectrum, specifically between 425-675nm. The lens is made from n-sf11 Schott material, a high index glass with excellent transmittance in the visible and near-infrared regions.
The lens features a plano-concave geometry, meaning one side is flat while the other is curved inward. The inner radius is 0mm, and the outer radius is also 0mm, indicating a sharp curvature on the concave side. The thickness at the edge of the lens is 5.39mm, while the thickness at the center is 3.5mm, demonstrating a gradual thinning towards the center.
The lens is coated with the EDM VIS-0 STD CURVE coating on both the front and back surfaces. This coating is designed to provide zero-degree angle of incidence performance for visible light, enhancing the lens's light transmission capabilities.
The lens is currently in stock and can be purchased directly from the Edmund Optics website using the provided weblink.