The 49-521 is a 9.0mm diameter Plano-Concave Lens with a focal length of -9, sourced from Edmund Optics. This lens is designed for use in the near-infrared spectrum, specifically for wavelengths between 600 and 1050nm.
The lens is made from n-sf11 Schott, a high-index glass with excellent optical properties. It features a plano-concave geometry, meaning one side is flat while the other is curved inward. This design is often used to diverge or spread out light, making it ideal for various applications such as beam expansion or collimation.
The 49-521 lens has a thickness of 3.63mm at the edge and 2.25mm at the center. The inner and outer radii are both 0, indicating a symmetrical curvature. The back focal length is -10.21mm, and the effective focal length is -9mm.
Both the front and back surfaces of the lens are coated with Edmund Optics' NIR-I standard curve coating. This anti-reflection coating is designed to minimize surface reflections and increase transmission in the near-infrared region, enhancing the lens' performance in its intended wavelength range.