The finely stratified sphere model was used to calculate electromagnet
ic fields inside homogeneous and radially inhomogeneous spheres which
are illuminated by electromagnetic plane waves. A complete picture of
the internal fields is given for spheres whose diameters are comparabl
e to the wavelength (alpha = 1.5 and 5, where alpha = 2 pi alpha/lambd
a is the size parameter of the sphere) and spheres whose diameters are
much larger than the wavelength (alpha as high as 150), for coated sp
heres (spheres composed of a homogeneous core and a homogeneous shell)
and gradient-index spheres (spheres with a continuous of refractive i
ndex), for spheres at states of morphology-dependent resonances (MDRs)
and those at non-resonant states.