AASERT 98: Ultrafast GaAs Photoconductivity and Applications for Radiation-Hard Electronics
Abstract
Finally, in the last year of the AASERT and during a no-cost extension period, an effort was made to demonstrate how pulsed, single-cycle terahertz beams generated and detected by nonstoichiometric-GaAs dipole antennas - could be employed as a tool for the imaging of metal and dielectric objects. This was accomplished through the use of the time-reversal and back-propagation of time-domain signals scattered from objects through off-axis diffraction. Experimental methods were devised and applied to the reconstruction of one- and two-dimensional objects in both transmissive and reflective geometries. The images produced in both simulation and experiment were able to resolve features less than both the peak and mcan wavelengths of the broadband THz pulses. It was empirically illustrated that this technique should be able to produce images rivaling those of an ideal diffraction-limited imaging system. Images comparable to those produced by conventional, direct (non-scattering) 1Hz imaging systems were also produced. These results from the time-domain, THz, off-axis imaging have 2 great deal of potential and hold promise that objects can be identified not just by their scattered time-domain signatures, but actually by their reconstructed shapes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2001
- Accession Number
- ADA409018
Entities
People
- John F. Whitaker
Organizations
- University of Michigan