An Achromat, or Achromatic lens, is usually made up of multiple optical elements, which can be air-spaced or cemented together. These typically alternate a positive lens of low index material, such as crown glass, and a negative lens of high index material, such as flint glass. The elements are selected and optimized so that dispersion in the positive element is corrected by the negative element, resulting in minimized chromatic aberration at two well-separated wavelengths. Achromats offer a nearly constant focal length across the visible spectrum, providing superior off-axis performance. Doublet lenses offer users many more design options than singlet lenses, which allows for superior performance in visual imaging and laser beam manipulation applications. Our lenses are computer designed, minimizing aberrations and providing a smaller focused spot size. They are offered with multi-layer or single-layer AR coatings. Standard diameters and focal lengths may be interchanged with our singlet lenses. Further, achromats are available in a wide variety of configurations, including positive, negative, triplet, and aspherized. These lenses are produced as doublets or triplets (three elements). The collimated beam should enter or depart from the surface (R₁ in drawing) with higher curvature (smaller radius) for optimized performance.

Our NIR Achromatic Lenses are computer optimized at infinite conjugate ratios for applications in the near-IR spectrum, producing the smallest spot size possible for polychromatic light sources between 750 to 1100 nm. Spherical and chromatic aberrations are minimized to provide superior performance. For most applications, diffraction-limited spot size can be achieved when using with monochromatic light sources of wavelength up to 2 µm.