Breaking the Diffraction Limit Manifold Using Specially Designed Metamaterial Split Ring Resonator

Abstract

A novel and efficient method to overcome the barriers of conventional diffraction limit using a specially designed metamaterial Split Ring Resonator (SRR) structure as an imaging sensor at microwave frequency is proposed. The topology of the proposed sensor is ingeniously designed to identify imaging objects having dimensions much less than the interacting wavelength λ. The split gap field region of the conventional SRR, used as the sensing region of the imaging sensor, is modified for enhancing the resolution capacity, by slightly raising the split region of the outer ring structure perpendicular to the plane of the resonator (Projected Split Ring Resonator — PSRR) which will reduce the area of the sensing region of the SRR probe considerably. The isolation of the structural parts of the SRR other than projected split region helps in using the localized evanescent field at the split region of the PSRR for imaging of minute objects having dimension ranges up to 0.0001λ by precisely choosing the split gap. The required projection height of the split region and the possible resolution limits of the PSRR sensor probe are evaluated by simulation. Experimental 2-dimensional sub-wavelength images obtained for various dielectric objects using a typical PSRR test probe having resolution capability up to 0.01λ are also presented.