Growing Shell The movie to left shows the scattered field intensity due to a glass sphere coated with a gold shell. Initially the thickness of the outer shell is 0.15 lambda (the wavelength of incident light) and is gradually reduced to 0. The size of the sphere remains constant throughout the simulation at 1.0 lambda. At first, the thick shell absorbs the light and there is no field inside the sphere. However, as the shell becomes thinner, modes start to appear in non-intuitive patterns. Finally, when the gold shell is almost gone, the glass sphere acts as a lens and a bright focal point can be seen. Illumination is from the bottom.