apochromatic

Definitions

  • WordNet 3.6
    • adj apochromatic corrected for both chromatic and spherical aberration "an apochromatic lens"
    • ***
Webster's Revised Unabridged Dictionary
    • a Apochromatic (Optics) Free from chromatic and spherical aberration; -- said esp. of a lens in which rays of three or more colors are brought to the same focus, the degree of achromatism thus obtained being more complete than where two rays only are thus focused, as in the ordinary achromatic objective.
    • ***
Century Dictionary and Cyclopedia
    • apochromatic An epithet descriptive of an improved form of lens devised by Professor Abbe of Jena, constructed of new kinds of glass which allow of a more perfect correction of chromatic and spherical aberration than has hitherto been possible. The kinds of glass employed are chiefly remarkable in that their dispersion for different parts of the spectrum is nearly proportional; hence a lens constructed of them is not subject to the limitation of an ordinary achromatic lens of being strictly achromatic for two colors only. Another defect of ordinary lenses, that their spherical aberration is not corrected for all rays, is also largely overcome.
    • ***

Etymology

Webster's Revised Unabridged Dictionary
Pref. apo-, + chromatic,