Optical N-BK7/ B270 /Fuses Silica double concave lens  

Double concave lens has two inward curved surfaces. Double Concave lens has negative focal length. Specifications: Material : Optical glass Diameter : 1mm ~ 300mm Focal Legnth Tolerance :+/-1% Diameter Tolerance :+0.0/-0.1mm Thickness Tolerance :+/-0.1mm Surface Quality :40/20 Centration :<3 arc minutes Clear Aperture :>90% Bevel : Protective bevel as needed Coating :Upon your request Realpoo Optics is a professional manufacturer of optical glass lenses, such as Spherical Lens, Glass Rod, Fresnel Lens, Diffraction Grating etc. The optics can be offered with coating or without coating. Welcome to send your inquiry.