Wave theory of virtual image [Invited]

The super resolution effect with virtual image was discovered about ten years ago using micron-sized transparent spherical dielectric particles. However, within the range of the corresponding size parameters, the simple approximation of geometric optics is not valid. Correct description of the virtual image needs the wave theory. Here we developed a novel theoretical method based on the wave theory of virtual image formation within a transparent dielectric sphere and discussed a few unusual effects arising in the frame of the wave theory.