RESONANCES AND POLES OF WEAKLY ABSORBING SPHERES

We found that the resonance positions for a weakly absorbing sphere ar e much different from those of a nonabsorbing sphere. The shifts of re sonance positions for Q(ext), Q(sca) and Q(abs), from their original r esonance positions for a real refractive index are different, and the formulas to describe these different kinds of shift are given. Calcula tions of 12 resonance cases show that our results are quite close to t hose given by exact Lorenz-Mie theory. We also derive the line shapes of the different resonances and calculate values for the resonance max ims and half-width as a function of absorption.