Image resolution and the properties of optical-wave target detection and imaging by using the NR-PC flat lens

We used the method of two-dimensional (2D) finite-difference time-domain (FDTD) to study the characteristics of optical-wave target detection and imaging from negative-refraction photonic crystal (NR-PC) flat lens in the paper. The theory of image resolution was introduced. The results show that there exists a transmission peak, with a value far greater than unit, resulting from the influence of the mini-forbidden bands and resonance excitation effect at resonance frequency. And, the refocusing of backscattered optical wave from the target leads to its image with a sub-wavelength lateral resolution and great amplitude as long as the target is placed at the focus of the NR-PC flat lens. And the application of NR-PC flat lens can be extended in optical area, especially in the detection and imaging of small target.