The 68-009 is a double-concave lens with a 9mm diameter and a focal length of -12mm, making it a negatively powered lens. This lens is sourced from Edmund Optics, a reputable vendor known for its high-quality optical elements. The lens is designed for use in the near-infrared (NIR) spectrum, specifically between 750nm and 1550nm, making it suitable for various applications in this range.
The lens is made from n-SF11 Schott, a high-index glass with excellent optical properties. This material is known for its low auto-fluorescence, making it ideal for applications that require low background noise. The lens features a double-concave geometry, with radii of curvature of -19.16mm for the front surface and 19.16mm for the back surface. This geometry results in a back focal length of -12.41mm.
The lens is coated with Edmund Optics' NIR-II standard curve coating on both the front and back surfaces. This coating is designed to enhance the lens' performance in the NIR spectrum, providing improved transmission and reduced reflectance. The coating is applied using a standard curve process, ensuring consistent performance across the lens surface.