LD1357-B N-BK7 Bi-Concave Lens; Dia:12.7 mm; f=-50.0 mm ARC 650-1050nm

The LD1357-B is a high-quality bi-concave lens offered by Thorlabs, a leading vendor in the optical industry. This lens, constructed from the renowned N-BK7 glass by Schott, is designed with a spherical shape and features a diameter of 12.7 mm and a focal length of -50.0 mm. The lens's geometry includes a 4.3 mm thickness at the edge and a 3.5 mm thickness at the center, providing a balanced structure for various applications.

The LD1357-B lens boasts an effective focal length (EFL) of -50 mm, calculated using the thin lens equation, which is a common parameter for characterizing lenses. The radii of curvature for the first and second surfaces are -52.1 mm and 52.1 mm, respectively, while the back focal length (BFL) is -51 mm. The lens's design incorporates an inner radius of 0 mm and an outer radius of 0 mm, ensuring optimal performance.

This lens is coated with Thorlabs' BBAR coating on both the front and back surfaces, specifically designed for the ARC 650-1050nm spectral range. This anti-reflection coating reduces surface reflections, enhancing overall transmission and improving the overall efficiency of the optical system.