This is a high-quality double-convex lens from the renowned optical vendor, Edmund Optics. The lens, identified as 89-249, boasts a diameter of 15mm and a focal length of 25mm, making it a versatile choice for various optical applications.
The lens is crafted from the esteemed N-BK7 Schott glass, a material known for its excellent optical properties, including high homogeneity, low auto-fluorescence, and superior transmittance across a wide spectrum. This particular lens is designed to operate optimally at a wavelength of 587.6nm.
The lens surfaces are coated with YAG-BBAR, a broadband anti-reflection coating that enhances transmission and reduces surface reflections. This coating is effective within the 500-1100nm wavelength range, making the lens suitable for a broad spectrum of applications.
The lens geometry is another notable feature. It has an edge thickness of 1.22mm and a center thickness of 3.5mm, with radii of curvature of 25.23mm for the first surface and -25.23mm for the second surface. The back focal length is 23.82mm, and both the inner and outer radii are 0mm, indicating a circular shape.