Coherence induced spectral changes and generalized radiance

L. Basano, Pasquale Ottonello, G. A. Rottigni +1 more

Robert Saunders

継雄 蒲

E. Wolf

It is generally taken for granted that the spectrum of light does not change on propagation. This belief is implicit in all spectroscopy. In the last few years it was discovered that while such spectral invariance holds for radiation from commonly used sources it does not hold, in general, because the spectrum of emitted radiation depends not only on the source spectrum but also on the coherence properties of the source. It was found that in some cases the induced changes may be appreciable, possibly resulting in frequency shifts of spectral lines. It has also been demonstrated that similar spectral changes may be produced by scattering on media whose dielectric susceptibility is appropriately correlated.

E. Wolf

Abstract : It is generally taken for granted that the spectrum of light does not change on propagation. This belief is implicit in all spectroscopy. In the last few years it was discovered that while such spectral invariance holds for radiation from commonly used sources it does not hold, in general, because the spectrum of emitted radiation depends not only on the source spectrum but also on the coherence properties of the source. It was found that in some cases the induced changes may be appreciable, possibly resulting in frequency shifts of spectral lines. It has also been demonstrated that similar spectral changes may be produced by scattering on random media whose dielectric susceptibility fluctuations are appropriately correlated. Very recently it was shown that under certain circumstances the frequency shifts generated by dynamic scattering may imitate the Doppler effect, even though the source, the scatterer and the observer are all at rest relative to each other. (emk)

David T. Attwood, Anne E. Sakdinawat