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Now showing items 51-60 of 72
Underlying terahertz vibrational spectrum of explosives solids
(AIP Publishing, 2008-07-08)
Using waveguide terahertz time-domain spectroscopy, we demonstrate the measurement of the underlying terahertz vibrational spectrum of the explosive solids hexahydro-1,3,5-trinitro-1,3,5-triazine, and 2,4,6-trinitrotoluene. ...
Subpicosecond electrical pulse generation using photoconductive switches with long carrier lifetimes
(AIP Publishing, 1989-03-13)
Using a new mechanism of electrical pulse generation, we have generated 350 fs (full width at half maximum) electrical pulses on a coplanar transmission line, fabricated on an unimplanted silicon-on-sapphire substrate.
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 ...
Nonlinear picosecond-pulse propagation through optical fibers with positive group velocity dispersion
(American Physical Society, 1981-09-28)
The predictions of the nonlinear Schrodinger equation have been tested by passing 5.5-psec optical pulses through a 70-m single-mode optical fiber. With use of a precise cross correlation technique based on pulse compression, ...
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 ...
Adiabatic compression of parallel-plate metal waveguides for sensitivity enhancement of waveguide THz time-domain spectroscopy
(AIP Publishing, 2005-02-02)
We demonstrate the efficient coupling of THz pulses into and out of an adiabatically compressed parallel-plate metal waveguide. The plate separation of the 63.5-mm long, compressed waveguide was fixed at 103 um at 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 ...
Properties of surface waves determined via bistatic terahertz impulse ranging
(AIP Publishing, 2001-02-19)
A bistatic terahertz impulse ranging system has permitted the full isolation and direct measurements of the surface wave loss and dispersion for terahertz frequencies on a dielectric cylinder. This system permits ranging ...
THz transverse electromagnetic mode two-dimensional interconnect layer incorporating quasi-optics
(AIP Publishing, 2003-11-03)
We report the demonstration of a planar THz interconnect layer capable of transmitting subpicosecond pulses in the transverse electromagnetic (TEM) mode over arbitrarily long paths with low absorption and no observable ...