Particle Photon vs. Wave Pictures of Spectroscopy

Even when the wavelength of the electromagnetic radiation is small relative to the length of the bulk molecular sample, it is often necessary to think of the matter - radiation interaction in terms of a bulk polarization induced by the radiation and detected via one or more coherence terms of the sample polarization (Mukamel, 1995). When the wavelength is small relative to sample size, 

The independent-photon and bulk-polarization spectroscopic communities use different aspects of the matter - radiation interaction to form the cartoons that help them to understand their experiments. The concepts and language are so different that communication between members of the different communities is often difficult. 

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