THz imaging, ranging, and applications

Summary form only given.Summary from only given. The combination of ultrashort optical pulses with micron scale dipole antennas permits generation of single cycle electromagnetic radiation. The pulses generate ultrawide band widths, which can cover two decades of frequency. These pulses have been used to perform electromagnetic scattering, or ranging, measurements with subpicosecond resolution. The use of near-impulse, ultrawide band excitation has particular advantages for ranging measurements. These include direct detection of the electric field, impulse excitation of targets, and measurement of electromagnetic scattering over a large bandwidth in a single measurement. The optical gating permits measurements with essentially zero jitter. The approximately 600 fs response time of the detector allows temporal discrimination of background reflections.