This is the 17-421 model from Edmund Optics, a 25mm diameter N-SF6 Precision NIR Aspheric Lens with an effective focal length of 50mm and a numerical aperture of 0.25, uncoated.
The lens is made of N-SF6 Schott, a high-quality optical material known for its excellent transmission properties in the near-infrared (NIR) region. The aspheric design of the lens helps to minimize spherical aberration, providing superior image quality.
The lens has an inner radius of 0mm and an outer radius of 0mm, with a thickness at the edge of 6.43mm. The effective focal length (EFL) is 50mm, and the numerical aperture (NA) is 0.25. The lens is uncoated, which means it does not have any anti-reflective coatings.
The geometry of the lens includes a center thickness of 8.5mm, a front diameter of 0mm, and a front surface error of 7.258095e-07. The curvature of the first surface (R1) is 38.13500018876825mm, and the curvature of the second surface (R2) is 0mm.
This lens is suitable for use in various applications that require high-quality imaging in the NIR region, such as optical metrology, beam shaping, and laser applications.