Modification of Dielectric Function to Account for Conductivity

we have ignored the polarization induced by the interaction of the wave with the boimd charge by setting s to sq. 

Since both E and H e the right hand side of this equation can be written as 

Now we want to represent isoot + a) in the above expression with ioiegs, where is a complex dielectric constant that incorporates the effects of the free electrons in tire medium. We set s = s + is where the prime and double prime are the real and imaginary parts, respectively. Equating these to the real and imaginary parts of isoor + a) from above, we 

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