Fraunhofer lines, (C) Wikipedia
Spectral absorption lines of the spectrum of the sun, named after the German physicist Joseph von Fraunhofer (1787–1826)
Such Lines are produced whenever a cold gas is between a broad spectrum photon source and the detector.
Photons are absorbed and then re-emitted in random new directions. Therefore the intensity in the original direction is lower and a dark line appears in the spectrum.
wavelength in nm | Fraunhopfer line | Lightsource | color |
---|---|---|---|
365.0146 | i | Hg | UV |
404.6561 | h | Hg | violet |
435.8343 | g | Hg | blue |
479.9914 | F' | Cd | blue |
486.1327 | F | H | blue |
546.0740 | e | Hg | green |
587.5618 | d | He | yellow |
589.2938 | D | Na | yellow |
643.8469 | C' | Cd | red |
656.2725 | C | H | red |
706.5188 | r | He | red |
768.2 | A' | K | red |
852.11 | s | Cs | IR |
1013.98 | t | Hg | IR |
See also Abbe-number, dispersion.