The 89-425 is a 5mm diameter, plano-convex lens with a focal length of 20mm, sourced from Edmund Optics. This lens is designed for use within the visible light spectrum, specifically between 425-675nm, and features a standard antireflection coating on both the front and back surfaces.
The lens's geometry includes an outer diameter of 5mm, a thickness at the edge of 1.15mm, and a center thickness of 1.5mm. The front surface has a radius of curvature of 9.17mm, resulting in a back focal length of 18.97mm. The lens is made from fused silica (mal-1965), ensuring high transmittance and resistance to thermal shock.
The 89-425 is a versatile lens, suitable for a wide range of applications that require a compact, high-performance optical element within the specified wavelength range. Its antireflection coating reduces surface reflections, thereby increasing transmission and minimizing optical losses.
Please note that the lens is spherical, which may cause some optical aberrations, particularly when used at wide apertures. However, these aberrations can be corrected with additional optical elements or by reducing the aperture size.