A lens assembly usually consisting of a convex crown glass element and a concave flint glass element. The opposing dispersion characteristics of the two glasses force two different wavelengths to converge at the same focal point. Beyond fixing color fringing, they also significantly reduce spherical aberration compared to simple lenses.
Heard on the job
We need an achromatic lens for the output collimator so the alignment beam and the IR laser stay collinear.
Also heard as
- achromat
Related terms
Achromat
An optical assembly designed to minimize chromatic aberration.
Spherical aberration
An optical defect where light rays passing through the edge of a lens focus at a different point than central rays.
Apochromat
A highly corrected lens that brings three distinct wavelengths of light to the same focal point.