Our cemented IR Achromatic Doublets, which are optimized at infinite conjugate ratios, are designed to work in the telecommunications region (1050 - 1700 nm). With design wavelengths at 1016 nm, 1330 nm, and 1550 nm, these achromatic doublets are useful for controlling chromatic aberration. They can also be used to achieve a diffraction-limited spot when using a monochromatic source like a laser.
An achromatic lens, also referred to as an achromat, typically consists of two optical components cemented together, usually a positive low-index (crown) element and a negative high-index (flint) element. In comparison to a singlet lens, or singlet for short, which only consists of a single piece of glass, the additional design freedom provided by using a doublet design allows for further optimization of performance. Therefore, an achromatic lens will have noticeable advantages over a comparable diameter and focal length singlet.
An achromatic lens is far superior to a simple lens for multi-color "white light" imaging. The two elements composing an achromatic lens (literally, "a lens with no color") are paired together for their ability to correct the color separation inherent in glass. Having eliminated the problematic chromatic aberrations, an achromatic lens becomes the most cost-efficient means for good polychromatic illumination and imaging.