Enhanced image resolution in photonic crystal structure by modification of the surface structure

In this paper, enhanced image resolution by modification in the two dimensional (2-D) photonic crystal structures has been proposed. The equal frequency contour (EFC) analysis have been done using plane wave expansion method which shows that the structure exhibits an effective isotropic refractive index, neff = -1 at a normalized frequency of ω = 0.2908(2πc/a) for TM polarization, located near the second band. At ω = 0.2908(2πc/a) for TM polarization, the considered PhC structure behaves as a superlens, as analyzed using the finite difference time domain (FDTD) method. The image resolution and stability of the photonic crystal slab lens has been enhanced by creating disorder in the top and bottom layer of the PhC structure. The intensity field distributions of the optimized structure exhibit the enhanced image quality with full width at half maximum (FWHM) of 0.311 λ. The proposed structure can also be used to sense the different type of blood constituents.