Evanescent field detection using negative refractive index lenses

In this paper, we define a sensitivity measure for evanescent field detectors and show that a dispersive and lossless DNG slab increases the sensitivity. Since evanescent field based measurement modalities have limited range of detection, we analyze the effect of the DNG lens on the range of the evanescent field detections. By increasing their range, evanescent field probes can be used for noninvasive detection of material properties with an increased sensitivity for deeper regions.