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Now showing items 11-18 of 18
Efficient generation of 380 fs pulses of THz radiation by ultrafast laser pulse excitation of a biased metal-semiconductor interface
(AIP Publishing, 1991-01-21)
We have demonstrated a new method of generating pulses of freely propagating THz electromagnetic radiation. The resulting 380 fs pulses are the shortest directly measured THz pulses in free space to date and are more ...
Nature of conduction in doped silicon
(American Physical Society, 1997-02-10)
Via ultrafast optoelectronic THz techniques, we are able to test alternative theories of conduction by precisely measuring the complex conductivity of doped silicon from low frequencies to frequencies higher than the plasma ...
Demonstrated low radiative loss of a quadrupole ultrashort electrical pulse propagated on a three strip coplanar transmission line
(AIP Publishing, 1997-11-10)
We present an approach for reducing the absorption and dispersion due to Cherenkov radiation on coplanar transmission lines, which does not require the reduction of the permittivity mismatch between the substrate and the ...
THz commensurate echoes: Periodic rephasing of molecular transitions in free-induction decay
(American Physical Society, 1991-04-08)
We report the first study of coherent transients excited by ultrafast pulses of THz radiation. Using a newly developed optoelectronic source of well-collimated beams of subpicosecond pulses of THz radiation to excite N2O ...
Observation of a Cole-Davidson type complex conductivity in the limit of very low carrier densities in doped silicon
(AIP Publishing, 1998-05-04)
Using THz time-domain spectroscopy to measure the complex conductivity of doped silicon from low frequencies to frequencies higher than the THz plasma frequency and the carrier damping rate, we were able to show in the ...
Electrical characterization to 4 THz of N- and P-type GaAs using THz time-domain spectroscopy
(AIP Publishing, 1992-08-17)
Using a high-performance optoelectronic THz beam system for time-domain spectroscopy, we have measured the absorption and index of refraction of N- and P-type doped GaAs from low frequencies to 4 THz. From these measurements ...
Line-shape transition of collision broadened lines
(American Physical Society, 1995-02-20)
Using the newly developed technique of THz time-domain spectroscopy, we have measured the far-wing absorption line profile of the ensemble of collision broadened ground state rotational lines of methylchloride vapor out ...
Trap-enhanced electric fields in semi-insulators: The role of electrical and optical carrier injection
(AIP Publishing, 1991-10-14)
We report extremely large field enhancement near the anode of an electrically biased metal/semi-insulator/metal structure. The large anode field results from a trap-enhanced space-charge region and is large enough to cause ...