Fig. 1. 3D numerical breast phantom

Single negative medium (SNG):

Single negative medium has imaginary refractive index because either permittivity or permeability is negative. As a result, at some point, electromagnetic field exhibit enhancement as a wave passing through a SNG medium. The following figure contains a waveguide with a slab embedded. The slab has the permeability of –1, and the permittivity of 1. Waveguide is operating below cutoff frequency to generate evanescent waves as only the evanescent part would contribute to the field enhancement. As seen on the left side of the slab, field displays “amplification”.

Research Interests

Current Projects:

  Particle scattering

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Metamaterials:

Double negative medium (DNG):

The bending in a different direction is because the propagation constant is negative.

This figure is another demonstration of back propagation in DNG medium. A wave is propagating from air into a slab (refractive index of -1) with an incident angle. As seen in the animation, wave is back propagating in the slab due to the phase lag caused by the negative refractive index. After leaving the slab, the wave keeps travelling forward with a positive phase delay.