Demonstration of self-imaging effect without paraxial approximation
The classical self-imaging effect can be observed for a periodic object with a pitch larger than the diffraction limit of an imaging system. In this paper, we show that the self-imaging effect can be achieved in an indefinite metamaterial even when the period is much smaller than the diffraction limit in both two-dimensional and three-dimensional numerical simulations, where the paraxial approximation is not applied. This is attributed to the evanescent waves, which carry the information about subwavelength features of the object, can be converted into propagating waves and then conveyed to far field by the metamaterial, where the permittivity in the propagation direction is negative while the transverse ones are positive. The indefinite metamaterial can be realized and approximated by a system of thin, alternating multilayer metal and insulator (MMI) stack. As long as the loss of the metamaterial is small enough, deep subwavelength image size can be achieved. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
Proceedings of SPIE - The International Society for Optical Engineering
Demonstration of self-imaging effect without paraxial approximation.
Proceedings of SPIE - The International Society for Optical Engineering,
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/12169