LB1027 N-BK7 Bi-Convex Lens; Dia:1 in; f=40.0 mm Uncoated

The LB1027 N-BK7 Bi-Convex Lens is a high-quality optical component sourced from Thorlabs, a leading vendor in the field of precision photonics. This lens, with a diameter of 1 inch and a focal length of 40.0 mm, is designed for use in a wide range of optical systems, including imaging, beam shaping, and laser applications.

The lens is made from N-BK7, a popular glass type known for its excellent optical properties. This material, also known as BK7, is a borosilicate crown glass with a low refractive index and low dispersion, making it an ideal choice for many optical applications. The N-BK7 designation indicates that this particular lens is made from Schott glass, a renowned manufacturer known for its high-quality optical materials.

The lens geometry is spherical, with both surfaces curved outwards, a design known as bi-convex. This shape is often used to collimate or focus light, making it a versatile choice for many applications. The lens has a center thickness of 6.1 mm and an edge thickness of 2 mm, providing robustness and durability.

The effective focal length (EFL) of the lens is 40.0 mm, a measure of its optical power. This value is calculated by taking the distance from the lens center to the point where the light rays converge or diverge. The back focal length (BFL) is 37.9 mm, the distance from the rear surface of the lens to the point where the light rays converge or diverge.

The lens is uncoated, meaning it does not have any anti-reflective coatings. While this can lead to higher losses due to reflection, it also means that the lens is less prone to damage and contamination.