 #1
PhysicsTruth
 116
 18
 Homework Statement:
 For a complex refractive index ##n^*=n+ik##, establish the relationship between the absorption coefficient and linear optical susceptibility. Take ##(n+ik)^2 = \epsilon = 1 + \chi##
 Relevant Equations:

##(n+ik)^2 = \epsilon = 1+ \chi##
##I=I_0 e^{\alpha z}##
##\alpha = \frac{4\pi k}{\lambda}##
##\alpha## is considered to be the absorption coefficient for a beam of light of maximum intensity ##I_0##. It's related to the complex part of the refractive index as we have shown above. Now, I have a doubt. Should I solve for ##k## from the quadratic equation in terms of the linear optical susceptibility ##\chi## directly, or should I assume a complex form of ##\chi## and separate the real and imaginary terms and then proceed?