The 69-656 is a 25mm diameter, 150mm focal length plano-convex lens, manufactured by Edmund Optics. This lens is made of Germanium burnett, a material well-suited for infrared applications due to its high refractive index and transparency in the infrared spectrum.
The lens features a front and back coating of EDM ARCEDGERMANIUM35, a broadband anti-reflection coating designed to minimize surface reflections and increase transmission in the 3-5µm wavelength range. This coating enhances the lens' performance in infrared applications, reducing losses due to reflection and improving overall system efficiency.
The lens has a spherical shape, with a radius of curvature of 450.58mm on the curved face. The center thickness of the lens is 3mm, while the edge thickness is 2.83mm. The lens has a zero inner radius and zero outer radius, indicating a plano surface on the opposite side of the curved face.
This lens is a valuable addition to any optical system operating in the infrared spectrum, offering high transmission, low reflection, and a long focal length in a compact package. It is currently in stock, according to the vendor's website.