AC508-400-AB-ML 50.8 mm Dia. N-BAK4/N-SF10 Mounted Achromatic Doublet; EFL=400mm 400-1100nm

The AC508-400-AB-ML is a high-quality achromatic doublet lens, designed and manufactured by Thorlabs. This lens is specifically engineered for use within the 400-1100nm wavelength range, making it suitable for a wide array of optical applications.

The lens features a 50.8 mm diameter, offering a substantial surface area for light transmission. The achromatic design, achieved through the use of N-BAK4 and N-SF10 Schott glass types, ensures minimal chromatic aberration, a common issue in optical systems. This is further enhanced by the anti-reflection (AR) coating on both the front and back surfaces, which reduces unwanted reflections and increases transmission efficiency.

The lens geometry is another notable feature. It has an edge thickness of 11.2 mm, providing structural rigidity. The inner and outer radii are zero, indicating a simple, circular shape. The first and second radii of curvature (r1 and r2) are 184.3 mm and -274 mm, respectively, suggesting a complex design that provides the necessary optical power while maintaining a compact form factor.

The lens also features a multiplet design, which is a combination of multiple lenses to achieve specific optical properties. In this case, the multiplet design contributes to the lens's achromatic performance.