Double lens element

BK7achromatic

Features AR Coated for the 400 - 700 nm Range Positive Doublet Sizes: Ø5 mm, Ø6 mm, Ø6.35 mm, Ø8 mm, Ø1/2", Ø1", Ø30 mm, and Ø2" Negative Doublet Sizes: Ø1/2", Ø1", and Ø2" 7.5 to 1000 mm Focal Lengths for Positive Doublets -20 to -100 mm Focal Lengths for Negative Doublets Thorlabs' cemented Achromatic Doublets are optimized to provide excellent performance in the visible region. Our design for the achromatic doublets uses the helium "d" line (587.6 nm, yellow) and the hydrogen "F" (486.1 nm, blue/green) and "C" (656.3 nm, red) lines since these wavelengths reasonably represent the visible spectrum and are used to define the Abbe Number, Vd, of a material. Refer to the Application tab above for information about the superior performance of achromatic doublets compared to singlet lenses and the Measurement tab for examples of measurements that can be made by downloading the appropriate Zemax® file for the achromatic lens of interest. Zemax files can be found by clicking on the document icon next to the appropriate part number below.