Quantum and semiclassical calculation of Regge pole positions and residues for complex optical potentials

Semiclassical and exact quantum methods have been used to make the first calculations of Regge pole positions and residues for singular complex optical potentials. The semiclassical pole positions are in excellent agreement with the quantum results. The semiclassical residues are less accurate, especially for the leading pole, but their accuracy rapidly improves as the pole number increases.