ACT508-750-A 50.8 mm Dia. N-BK7/N-SF2 Unmounted Achromatic Doublet; EFL=750mm 400-700nm

The ACT508-750-A is a high-quality achromatic doublet lens, unmounted and with a diameter of 50.8 mm, sourced from the renowned optical component manufacturer, Thorlabs. This lens is designed for use within the 400-700nm wavelength range, making it suitable for a wide array of applications within the visible light spectrum.

The lens features a focal length of 750mm, indicated by the 'EFL' parameter in its name. This long focal length is beneficial in applications requiring a narrow field of view or high magnification. The achromatic design of the lens ensures that it effectively compensates for chromatic aberration, a common issue in optical systems where different wavelengths of light are focused at different points.

The lens is composed of two elements, made from N-BK7 and N-SF2 Schott glass. These materials were chosen for their excellent optical properties, including high transparency and low dispersion. The lens is coated with tho ac400-700-a, a proprietary coating developed by Thorlabs, which further enhances its performance by reducing surface reflections and increasing transmission.

The geometry of the lens is carefully crafted, with an edge thickness of 11mm and central thicknesses of 6mm for both surfaces. The lens features two radii of curvature, r1 and r2, of 398.6mm and -343.7mm respectively, and a third radius, r3, of -1544.5mm. These parameters contribute to the lens's overall optical performance.