The Negative Meniscus (Convex-Concave) Lens is an essential component in advanced optical systems, meticulously designed to minimize spherical aberration. This lens features a unique shape with a smaller center thickness, allowing it to effectively increase the focal length and decrease the numerical aperture (NA) when used in combination with other lenses. Its design is particularly advantageous in applications where light needs to be diverged, ensuring that the convex surface faces the beam to achieve optimal performance.

Each Negative Meniscus Lens is crafted with precision, offering focal lengths ranging from -100.0 to -1000.0 mm, with a tolerance of ±1%. The diameter of these lenses varies from 3.0 mm to 200.0 mm, providing a wide selection to suit various optical setups. The quality of the lens is evident in its surface specifications, with scratch and dig ratings of 80/50 to 20/10 and spherical surface power and irregularity measured in fringes. These specifications ensure that the lens delivers superior optical clarity and performance.

To further enhance the functionality and durability of the Negative Meniscus Lens, it can be coated with magnesium fluoride (MgF2) to protect its surface or treated with anti-reflective (AR) coatings to increase light transmission. The precise calculation of the focal length is achieved using the formula: f = (R1 * R2) / ((n-1) * (R2-R1)), where n represents the index of refraction, and R1 and R2 denote the radius of curvature for each lens surface. This meticulous attention to detail ensures that each lens delivers impeccable performance in demanding optical applications.