AC508-400-C 50.8 mm Dia. N-BAF10/N-SF6 Unmounted Achromatic Doublet; EFL=402.7mm 1050-1700nm

The AC508-400-C is a 50.8 mm diameter achromatic doublet lens, designed and manufactured by Thorlabs. This unmounted lens is specifically engineered for use within the 1050-1700nm wavelength range, making it suitable for a variety of applications within the near-infrared spectrum.

The lens features a complex geometry, with a central thickness of 6.5mm and edge thickness of 7.8mm. The curvature of the lens is defined by three radii: r1 at 125.6mm, r2 at -161.5mm, and r3 at 376.3mm. The lens is constructed from two types of Schott glass, N-BAF10 and N-SF6, each with its own specific refractive index and dispersion properties. This combination of materials and curvatures helps to correct chromatic aberration, ensuring high-quality imaging across the specified wavelength range.

Both the front and back surfaces of the lens are coated with Thorlabs' AC1050-1700-C coating, which is designed to enhance transmission within the 1050-1700nm range. This coating helps to reduce surface reflections, improving the overall efficiency and quality of the lens.

The lens is classified as a multiplet, indicating that it is composed of multiple elements. This design allows for more precise control over the optical properties of the lens, making it suitable for high-performance applications. Despite its complexity, the lens is unmounted, providing users with the flexibility to integrate it into their own systems and setups.