" At least two significant roles for large scale quantum coherence in living systems have been suggested: Herbert Fröhlich’s coherent excitations of nonlinearly coupled ensembles of large polarizable molecules, with frequencies in the microwave region, and Fritz Popp’s coherent visible photon emission arising from metabolically active cells. The large difference in frequencies has made it difficult to see these two phenomena as being linked. Here a case is made for a potentially large coupling between these modes, and suggestions are made for the biological roles played by these coherent excitations."
Author estimate that about 400 Fröhlich photons (microwave frequency) can be coupled to a Popp photon.
" .. Qualitatively, however, one might expect a low probability for a few photons to couple, a large probability for about 400, and a flattening off thereafter with increasing numbers."
The picture that author posit is:
" • there are at least two types of quantum electromagnetic systems associated with the living state. One is in the microwave frequency range as suggested by Fröhlich, and one is around the visible region as suggested by Popp
There are sections in the web dedicated both to biophoton  and Fröhlich  emissions.
Last modified on 20-Mar-16