Meniscus Lens Positive Meniscus Lens Negative Meniscus Lens

A meniscus lens is a lens with two spherical surfaces, convex on one side and concave on the other. The lens provides a smaller beam diameter to reduce beam waste and spherical aberration. When one meniscus is combined with another lens, the focal length is shortened and the numerical aperture of the system is increased. This reduces image distortion and improves image resolution.   There are two types of meniscus lenses: ● Positive meniscus lens The positive meniscus lens is used for applications requiring small focal numbers (less than 2.5). For focal lengths between 2.5 and 10, a meniscus lens minimizes spot size and improves image quality. The concave side curvature of a positive lens is smaller and the convex side curvature is larger.   Frequently used for beam focusing applications   Minimizes the increase in spherical aberrations for multi-element systems   ● Negative meniscus lens The negative meniscus lens is used for applications using infrared materials with a high refractive index. These lenses serve as substitutes for other negative lenses with greater curvature on the concave side and less curvature on the convex side. They are used in beam spreading applications where minimal spherical aberration is required.   Frequently used for beam expanding applications   Minimizes the increase in spherical aberrations for multi-element systems   Parameters Material  Optical Glass Surface Flatness  < λ/5 @ 633nm Scratch/Dig  < 40/20 (both sides) Eccentricity  ≤ 1arcmin Focal Length Tolerance  < ± 1% Diameter Tolerance  < + 0.00/ - 0.02mm Thickness Tolerance  < ± 0.05 Clear Aperture  ≥ 95% of diameter   Oplens provide custom optical components, we can custom sizes and shapes. If you are interested in any of our products, please click here.