LB1309-A N-BK7 Bi-Convex Lens; Dia:2 in; f=75.0 mm ARC 350-700nm

The LB1309-A is a high-quality bi-convex lens manufactured by Thorlabs, a leading global supplier of photonics equipment. This lens boasts a diameter of 2 inches (50.8 mm) and a focal length of 75.0 mm, making it suitable for a wide range of optical applications.

The lens is made from N-BK7, a popular optical glass due to its excellent optical properties and high damage threshold. The N-BK7 material ensures high transmission in the visible spectrum, specifically designed for the 350-700 nm range. This makes the LB1309-A an ideal choice for applications that require high-transmission optics, such as laser systems, microscopy, and beam shaping.

The lens features a spherical shape with radii of curvature of 75.2 mm for the first surface and -75.2 mm for the second surface. This bi-convex design provides a large acceptance angle and low spherical aberration, ensuring high-quality imaging and light transmission. The lens has an effective focal length (EFL) of 75 mm and a back focal length (BFL) of 71 mm.

The LB1309-A is coated with Thorlabs' anti-reflection coating, which significantly reduces surface reflections and increases transmission. The coating is applied to both the front and back surfaces, ensuring high transmission and low loss.