LA1257-A N-BK7 Plano-Convex Lens; Dia:25.0 mm; f=75.0 mm ARC 350-700nm

The LA1257-A is a high-quality plano-convex lens from Thorlabs, designed with a circular base shape and a spherical geometry. This lens is fabricated from the renowned N-BK7 glass, a popular choice in the optical industry due to its excellent optical properties. The lens has a diameter of 25.0 mm and a thickness of 2.02 mm at the edge, while the center thickness measures 4.1 mm.

The LA1257-A lens boasts an effective focal length (EFL) of 75.0 mm, making it suitable for a wide range of applications. The front radius of curvature (R1) is 38.6 mm, and the back focal length (BFL) is 72.2 mm. The lens does not have an inner radius, and the outer radius is also 0, indicating a uniform curvature.

This lens is designed for use with a wavelength of 632.8 nm, and it comes with anti-reflection coatings on both the front and back surfaces. These coatings, identified as "tho a bbar," are specifically designed to reduce reflection and increase transmission within the 350-700 nm spectral range.