Propagation along the optic axis for wavelengths pitch

We shall first consider the propagation of light along the optic axis for wavelengths much smaller than the pitch so that reflexion and interference 

The basic principle underlying the Jones method is that any elliptic vibration can be represented by the column vector 

The effect of an optical system - comprised, say, of birefringent, absorbing and dichroic plates - is to change A and A, so that 

Let the principal axes of the first layer be inclined at an angle p with respect to x,y. If light is incident normal to the layers, i.e., along z, the 

Jones retardation matrix for the first layer referred to its own principal axes is given by 

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