Influence on the resolution based on defective NR-PC double flat lens group with Ag for target detection and imaging

•We study the photonic crystal lens, which overcome the optical diffraction limit.•We use dynamic scanning to detect the small target (smaller than the λ).•Introducing defect into the NR-PC flat lens can improve the resolution.•Introducing defect with Ag to NR-PC flat lens can further improve the resolution.

In this paper, we employed the dynamic scanning scheme to study the influence on target detection and imaging based on the defective NR-PC double flat lens group with Ag by finite-difference-time-domain method. We firstly deduced the focusing imaging circuit diagram of NR-PC flat lens with the Snell extension law and geometrical optics principle. Numerical simulations indicate that significant enhancement of the scattering signal can be obtained while the NR-PC flat lens is used for target detection and imaging. Then the imaging principle of NR-PC flat lens group is studied. We find that the distance between the two lenses can be adjusted flexibly. What is important, the resolution of target detection is greatly improved when incorporating Ag into the NR-PC flat lens group. In conclusion, our investigation makes the target detection and imaging by NR-PC flat lens come true, and optimizes the performance of small target detection and imaging system.