Bridging Technique for Calculating the Extinction Efficiency of Arbitrary Shaped Particles

A general bridging technique is developed to calculate the extinction efficiency of particles by combining the extended RayleighDebye approximation and the modified anomalous diffraction theory. Comparisons with the exact methods are performed for spheres, spheroids, infinite cylinders, and finite cylinders. The overall features of the extinction efficiencies calculated from the new, to our knowledge, bridging method are in agreement with those calculated from the exact methods. Also discussed are accuracy of the new method and its domain of applicability. The new technique can be potentially applied to particles of virtually any shapes and sizes.