Subwavelength imaging of a point source based on two-dimensional photonic crystals.

Abstract

A new two-dimensional (2D) photonic crystal (PC) structure with effective refractive index approaching -1, consisting of periodic array air holes in silicon, is proposed. The light radiated from a point source can form an image through a single wedge PC. Numerical results show that the half-width of the image reaches 0.44λ, which is lower than half of the incident wavelength. In addition, the light through the combination of two of the same PCs can also form subwavelength imaging of which the half-width reaches 0.67λ, and the image almost flipped 180° compared with a point source.