        MyCTMainForum  n (Sellmeier equation)

Optics index               The Sellmeier equation uses the Kramers-Kronig relationship between optical absorption and refractive index to calculate the wavelength-dependant refractive index based on constants relating to key absorbances.              B1 C1 m² --- METRIC --- nm² µm² mm² cm² km² -- IMPERIAL -- square inches sqare feet square yards square miles --- OTHER --- hectares acres dunams square chains tennis courts B2 C2 m² --- METRIC --- nm² µm² mm² cm² km² -- IMPERIAL -- square inches sqare feet square yards square miles --- OTHER --- hectares acres dunams square chains tennis courts B3 C3 m² --- METRIC --- nm² µm² mm² cm² km² -- IMPERIAL -- square inches sqare feet square yards square miles --- OTHER --- hectares acres dunams square chains tennis courts Wavelength m --- METRIC --- pm nm microns (µm) mm cm km -- IMPERIAL -- mil 1/16 inch inches feet yards miles - SCIENTIFIC - Planck Bohrs Angstrom light-seconds light-years au parsecs --- OTHER --- points cubits fathoms rods chains football fields furlongs Roman miles nautical miles leagues Refractive index   Fill in the Sellmeier coefficients for a given substance in the blue boxes, along with a wavelength of interest, and the refractive index will be given in the orange box.
The sellmeier "B" coefficients are the oscillator strengths of transitions, and the "C" coefficients are the squares of the respective transition energies (as photon wavelengths). Thus, knowing the experimental or calculated absorption spectrum of a substance, it is possible to predict the refractive index.          