An achromatic lens is corrected to focus two wavelengths (usually red and blue) on the same plane and is made to minimize the effects of chromatic and spherical aberration. Achromatic doublets are the most prevalent variety of achromat, and flint glass and crown glass are the most often utilized materials in their production. Torrent Photonics' achromatic doublet lenses are better off-axis than singlet lenses and feature a focal length independent of aperture and operating wavelength. To do this, a multielement design reduces the lens’ chromatic aberration. In addition, better broadband performance than spherical singlets or aspheric lenses is achieved by the doublet’s second (negative) element compensating for the first (positive) element’s dispersion. Torrent’s doublets, which range in diameter from 3mm to 9mm, are frequently seen in analytical and medical equipment.
