Scalar product positive determinancy

For a monolayer of dye molecules, Aq may be much smaller than unity. Then, we have an approximated expression of p/s=AAp/AAs [34]. The absorption by the chromophore in the thin film is determined by the square of the scalar product of the two vectors the electric dipole moment of the chromophore and the standing wave electric field of the light at the position of the chromophore. Therefore, AA is proportional to the square of the scalar product of reduced forms (remember that the oxidized form is presumed to be colorless). 

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