Sub-wavelength imaging and negative refraction measurement of triangle prism

Sub-wavelength imaging, which can transform evanescent wave into travelling wave and utilize wave component with small wave-vector, is receiving much study interest. Both negative refraction and beam forming can realize sub-wavelength imaging, and their mechanism are analyzed and compared. The refraction behavior under different incident angle is measured experimentally, and it is found that larger incident angle is better for near field energy transfer, while smaller incident angle is better for detection application.