The application of dynamic scanning in target detection and imaging based on an NR-PC flat lens

In this paper a finite-difference time-domain method is used to model and analyze the application of dynamic scanning in target detection and imaging by using an effective negative-refraction photonic crystal(NR-PC) flat lens.The results show that there is a transmission peak,with a value far greater than unity,resulting from the influence of mini-forbidden bands and resonance excitation effect at a resonance frequency of 0.3068(a/λ).Thus,the lightwave emitted from the point source will provide strong backscattered waves after being focused on the target by the NR-PC lens that greatly improves the refocusing resolution and imaging resolution of the backscattered wave.Furthermore,a comparison with a non-dynamic scanning scheme clearly demonstrates that the dynamic scanning scheme provides improved refocusing resolution.In conclusion,our investigation optimized the performance of a detection and imaging system,and provided the basis for converting an idealized LHM lens into a physically realizable NR-PC flat lens.