Near-Field Near-Infrared and Microwave Microscopy

Charlie Symons, Joseph Medendorp

Transmission-mode near-field scanning microscopes (NSM) in the near-infrared and microwave spectral regions are being modeled to provide understanding of near-field optics and imaging. Near-field spectrometric imaging involves the electromagnetic scattering characteristics of objects illuminated by the near field of a sub-wavelength-sized aperture. In this project some unusual phenomena are being investigated, including a near-field focusing effect, as well as an impedance-based image-shape effect. Two computational models have been used to characterize NSMs, moment-method and finite-difference time-domain models. These two models are being applied to the analysis of the NSM for various configurations, and experimental near-field imaging measurements are compared with numerical predictions.