Common form for arbitrary polarization

It should be pointed out that the expression for d r/dQ given in equ. (9.7c) can also be derived if one does not consider the specifically selected kinds of polarization, but stays within one polarization basis only. Selecting the linear basis (see Section 9.2.2), one then has to add in equal portions the contributions from unpolarized and circularly polarized light to /(lin x) and /(lin y). This increases the values for the linearly polarized components to Ix and Iy given by 

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