Achromat

Compared with singlet lenses, Betensh's achromats are optimized to provide a focal length independent of aperture and operating wavelength and have superior off-axis performance. This is accomplished by utilizing a multielement design to minimize the chromatic aberration of the lens. Dispersion in the first (positive) element of the doublet is corrected by the second (negative) element, resulting in better broadband performance than spherical singlets or aspheric lenses. Betensh's achromats with diameter 3mm to 9mm are widely used in many analytical and medical devices.