MARCH 1997 REPORT FOR

W. CHARLES SYMONS, III

With the 1997 Pittsburgh Conference rapidly approaching, preparation for the presentation entitled NEAR-FIELD OPTICS APPLIED TO NEAR-INFRARED IMAGING took top priority. To this end, several Finite Difference Time Domain (FDTD) simulations were run on the University of Kentucky's Convex Exemplar. These simulations were utilized to verify the high resolution capability of the Near-Field Scanning Optical Microscope (NSOM). This verification was accomplished by utilizing a gaussian pulsed source such that a discrete Fourier transform could be utilized to obtain the amplitude incident on the detector at the frequency of interest. In this manner, several runs were performed with the subwavelength aperture being raster-scanned across the wire sample thereby creating the cross sectional image in Figure 1 below. Furthermore, several time-domain images were computed on the sample side of the subwavelength aperture both with and without the subwavelength wire sample in order to visualize the near-field effects of such an instrument.

Figure 1: Cross-Sectional NSOM Image of Subwavelength Wire.

Figure 2: Time-Domain Images of NSOM model (z=0 plane).