The wavelengths generally are in red and blue colour. The most commonly used and the earliest example of an achromatic lens is the achromatic doublet. An achromatic doublet is made from a pair of ...

1 Pacific Northwest National Laboratory, Richland, WA, United States 2 Department of Chemistry, University of Washington, Seattle, WA, United States As of 2024, the use of X-photoelectron spectroscopy ...