THE MORPHOLOGY DEPENDENT RESONANCE DOES NOT REQUIRE DISCONTINUITY OF THE REFRACTIVE-INDEX AT THE SPHERE SURFACE

The extinction efficiency of an electromagnetic wave for a sphere that has a homogeneous core with a refractive index m(r) = 1.33 and a shel l with variable refractive index, where r is the radial coordinate, wa s calculated by using a finely stratified sphere model. m(r) changes s moothly from 1.33 at the core surface to 1.0, the refractive index of the medium, at the sphere surface while dm(r)/dr is continuous. Morpho logy dependent resonances are similar to that of a homogeneous sphere when the shell is thin and still exist when the shell is thick (20% of the radius). What influences the MDR's most is the average refractive index of the edge region.