LB11-12-20 12.7 mm Dia. N-BK7 Double-Concave Lens; EFL=-20mm Uncoated

This is a high-quality spherical lens from CeNing Optics, specifically designed for use in optical systems that require a concave-concave lens shape. The lens has a diameter of 12.7 mm and a center thickness of 2 mm, making it suitable for applications where space is a constraint.

The lens is made from N-BK7, a popular glass type known for its excellent optical properties. This material, also known as Schott glass, is widely used in the optical industry due to its low dispersion and high Abbe number. The N-BK7 Schott glass used in this lens ensures high-quality imaging with minimal chromatic aberration.

The effective focal length (EFL) of this lens is -20 mm, indicating that it is a double-concave lens. This type of lens is used to diverge light, making it ideal for applications such as beam expansion or collimation. The lens's inner and outer radii are -21.08 mm and 21.08 mm, respectively, which are crucial specifications for designing and simulating optical systems.

The lens is uncoated, meaning it does not have any anti-reflective or other surface coatings. While coatings can enhance the performance of a lens by reducing reflections or increasing transmission, an uncoated lens can be advantageous in certain applications, such as when cost or simplicity is a priority.

According to the provided data, this lens is in stock and available for immediate purchase. For more information, please refer to the vendor's website, which is provided in the item data.