LB1889-B N-BK7 Bi-Convex Lens; Dia:2 in; f=250.0 mm ARC 650-1050nm

The LB1889-B is a high-quality bi-convex lens from Thorlabs, designed for use in a wide range of optical applications. This lens is fabricated from N-BK7, a popular borosilicate glass known for its excellent optical properties, making it an ideal choice for applications that require high-performance lensing.

The lens features a diameter of 2 inches (50.8 mm) and a focal length of 250.0 mm. The bi-convex design, characterized by two spherical surfaces that curve outwards, provides a high degree of focusing power. This design is particularly useful in applications where a tight focus is required, such as in microscopy or beam shaping.

The lens has a central thickness of 5.5 mm and an edge thickness of 3 mm, providing robustness and durability. The edges are also rounded, reducing the risk of damage during handling and installation.

The LB1889-B is coated with Thorlabs' Broadband Anti-Reflection coating, which is designed to minimize surface reflections and increase transmission across the 650-1050 nm spectral range. This coating ensures optimal performance in a variety of applications, including laser systems, bio-imaging, and spectroscopy.