Alkor Technologies manufactures custom achromatic doublet lenses made of optical glasses
A single lens used to form an image will always show some chromatic aberration, that is variation of focal length with wavelength. Achromatic doublet lenses correct for this as they are constructed from two different glass types and designed to remove first order chromatic aberration. Generally spherical aberration is reduced at the same time. Achromatic doublets are widely used to form images, for example telescope objectives, and also to focus laser beams.
An achromat consists of a positive low-index crown glass lens element cemented to a negative high-index flint glass lens element. The elements are chosen so as to cancel chromatic aberration at two well separated wavelengths; usually in the blue and red region of the spectrum. Focal length is constant at those two wavelengths and focal length shifts are virtually eliminated across the visible wavelengths. All of our achromats are available with a single-layer MgF2 broadband antireflection coating to increase transmission throughout the visible spectrum.
Contact our Sales Team for pricing for any custom size and coatings requirements.