LC1258-B N-BK7 Plano-Concave Lens; Dia:25 mm; f=-75.0 mm ARC 650-1050nm

The LC1258-B is a plano-concave lens with a diameter of 25 mm and a focal length of -75.0 mm, making it suitable for a wide range of optical applications. This lens is fabricated from N-BK7, a popular borosilicate glass known for its excellent optical properties, including high transparency across a broad spectrum. The lens is sourced from Thorlabs, a reputable vendor in the optical industry.

The LC1258-B features a plano-concave geometry, meaning one side is flat while the other is curved inward. This design is often used to diverge or spread out light, making it ideal for use in beam expanders, laser systems, and other applications where light needs to be distributed over a larger area.

The lens has a thickness of 5.6 mm at the edge and 3.5 mm at the center, providing structural integrity and ensuring efficient light transmission. The effective focal length (EFL) is -75 mm, a value that is negative due to the concave shape of the lens. The radius of curvature (R1) is -38.6 mm, and the back focal length (BFL) is -77.3 mm.

The lens is coated with a broadband anti-reflection coating, specifically designed for the 650-1050 nm range. This coating reduces surface reflections, enhancing the lens's transmission efficiency and overall performance. The coating is applied to both the front and back surfaces of the lens, ensuring optimal performance from both sides.