Three-Dimensional THz Imaging
Abstract
Three-dimensional imaging has been demonstrated using a single-cycle terahertz electromagnetic pulses. Reflection-mode imaging was performed with photoconductive transmitter and receiver and a reconstruction algorithm based on time reversal. A two-dimensional array was synthesized from ten concentric ring annular arrays with numerical apertures ranging from 0.27 to 0.43. The system clearly distinguished image planes separated by 1.5 mm and achieved a lateral resolution of 1.1 mm. In terms of the illuminating terahertz power spectrum, the lateral resolution was 28% and 81% of the peak and mean wavelengths, respectively, Coded excitation has also been explored to improve the signal-to-noise ratio. A separate imaging system was constructed, where a 54-bit binary waveform is transmitted while the received signals are digitally compressed. Two-dimensional objects have been imaged with a 13 dB improvement in signal-to-noise ratio.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 20, 2005
- Accession Number
- ADA434536
Entities
People
- Theodore B Norris
Organizations
- University of Michigan