57 results about "Abbe number" patented technology

In optics and lens design, the Abbe number, also known as the V-number or constringence of a transparent material, is a measure of the material's dispersion (variation of refractive index versus wavelength), with high values of V indicating low dispersion. It is named after Ernst Abbe (1840–1905), the German physicist who defined it. The Abbe number, VD, of a material is defined as VD=(nD-1)/(nF-nC), where nC, nD and nF are the refractive indices of the material at the wavelengths of the Fraunhofer C, D₁, and F spectral lines (656.3 nm, 589.3 nm, and 486.1 nm respectively).