Zemax Files
Click on the red Document icon next to the item numbers below to access the Zemax file download. Our entire Zemax Catalog is also available.

Features

• Best Possible Performance from a Spherical Singlet
• Uncoated Design for High Power Applications
• Ideal for High-Power Applications
• Diffraction-Limited Performance at Small Input Diameters

Thorlabs' N-BK7 Best Form lenses are designed to minimize spherical aberration while still using spherical surfaces to form the lens. They are typically employed at infinite conjugates in high-power applications where doublets are not an option. The lenses presented here are uncoated. Versions of our best form lenses are also available with one of three antireflection coatings deposited on both surfaces to reduce the light reflected from each surface of the lens (see table to the right).

For spherical lenses, a given focal length can be produced by more than one combination of the front and back radii of curvature. Each combination of surface curvatures will result in a different amount of aberration caused by the lens (see the Graphs tab). The radius of curvature for each surface of these "best form" lenses has been chosen to minimize the spherical aberration and coma produced by the lens, optimizing it for use at infinite conjugates. This process makes these lenses more expensive than plano-convex or bi-convex lenses, but still significantly less expensive than our premium line of CNC-polished aspheric lenses. Since the lenses are optimized for minimum spot size, they can theoretically reach diffraction-limited performance for small input beam diameters (see the table below for details).

For best performance in focusing applications, place the surface with the shorter radius of curvature (i.e., the more steeply curved surface) towards the collimated source. Lens kits are also available. Please click here for more information.