Large object distance and super-resolution graded-index photonic crystal flat lens.

ABSTRACT

In order to realize super-resolution imaging of point source at any positions within a large object distance range, a graded-index equivalent medium (GEM) flat lens, which can break through the object distance limit d (d is the lens thickness), is analyzed by negative refraction. Based on this analysis, graded-index photonic crystal (GPC) flat lens with a large object distance is designed. Its imaging resolution can reach up to 0.4λ at the maximum object distance of 5d, which breaks through the diffraction limit.