Polarization propagator time domain

It is often also called the polarization propagator in the time domain (Zubarev, 1974 Linderberg and Ohrn, 1973 J0rgensen and Simons, 1981), while mathematically it is a double-time Green s function. 

Exercise 3.8 Derive the expression for the polarization propagator in the frequency domain, Eq. (3.110), from the expression in the time domain, Eq. (3.107). 

For arbitrary angle 4) or director axis angular and spatial distributions, and more complicated cell structure, the phase shift, and therefore the transmission of light through the cell and other accompanying polarization selective elements, is not amenable to simple analytical treatment. More sophisticated Jones matrix methods or nmnerical technique such as the finite difference time domain (FDTD) nmnerical methods discussed in the next chapter are needed to solve such a complex propagation problem. 

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