Thickness dependence of two-dimensional photonic quasicrystal lens imaging characteristics

The dependence of imaging characteristics on lens thickness for a germanium-cylinder-based decagonal photonic quasicrystal lens has been studied. Results showed that, when the thickness is equal or close to that of the circular main channels of the photon stream the lens can easily focus and image. It is reported for the first time qualitatively in a diagram in this work. The convergences of light waves and levels of imaging stability are closely correlated with thicknesses and strength of quasi-periodicity of lens. As lens thickness increases, surface conditions of lens change irregularly, causing imaging characteristics to vary non-monotonically.