The 69-684 is a 25mm diameter, 35mm focal length plano-convex lens, manufactured by Edmund Optics. This lens is made of silicon, specifically silicon sal vil 1957, and features a broadband anti-reflection (BBAR) coating on both the front and back surfaces. The BBAR coating is designed to reduce reflection losses over a wide range of wavelengths, making this lens particularly suitable for applications in the 3-5µm spectral region.
The lens has a plano-convex geometry, meaning one side is flat (plano) and the other side is curved (convex). The radius of curvature of the convex surface is 84.62mm. The lens has a thickness of 2.07mm at the edge and 3mm at the center. The effective focal length (EFL) of the lens is 35mm.
This lens is available from Edmund Optics and is currently in stock. It is part of their extensive catalog of optical elements, which includes a wide variety of lenses, mirrors, beam splitters, and other optical components. The lens is suitable for use in a variety of applications, including imaging, spectroscopy, and beam shaping.