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Now showing items 11-20 of 72
Electrical characterization of conducting polypyrrole by THz time-domain spectroscopy
(AIP Publishing, 2000-10-16)
Using an optoelectronic THz beam system for THz time-domain spectroscopy (THz TDS), we have measured the absorption and index of refraction of a conducting polypyrrole film from low frequencies to 2.5 THz. From these ...
Parallel plate THz transmitter
(AIP Publishing, 2004-02-02)
A THz transmitter that directly excites the guided wave modes of a dielectric filled parallel plate waveguide is demonstrated. When coupled to free space, the transmitter yields a large peak time-domain THz signal. The ...
THz time-domain spectroscopy of high Tc substrates
(AIP Publishing, 1990-09-03)
Using the method of time-domain spectroscopy, we have measured the absorption and dispersion from 0.2 to 2 THz of the high Tc substrates, magnesium oxide, yttria-stabilized zirconia (YSZ), and lanthanum aluminate. Our ...
Velocity distributions of sputtered excited atoms
(American Physical Society, 1982-02-08)
The first direct measurements are reported of the velocity distributions of sputtered atoms in excited states with electronic configurations completely different from the ground state. In contrast to previous work, the ...
Observation of electromagnetic shock waves from propagating surface-dipole distributions
(American Physical Society, 1989-06-19)
We have directly measured the time-dependent electromagnetic shock wave generated by an electric surface-dipole distribution propagating faster than the phase velocity in the underlying dielectric substrate. The results ...
Highly sensitive terahertz measurement of layer thickness using a two-cylinder waveguide sensor
(AIP Publishing, 2010-08-17)
We report on the layer thickness determination on dielectrically coated metal cylinders using terahertz (THz) time-domain spectroscopy. A considerable sensitivity increase of up to a factor of 150 is obtained for layers ...
Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors
(Optical Society of America, 1990-10)
Using the method of time-domain spectroscopy, we measure the far-infrared absorption and dispersion from 0.2 to 2 THz of the crystalline dielectrics sapphire and quartz, fused silica, and the semiconductors silicon, gallium, ...
Ultrafast light-controlled optical-fiber modulator
(AIP Publishing, 1987-04-06)
We report the ultrafast operation of a light-controlled optical-fiber modulator, driven by subpicosecond, compressed, and amplified (6000 A) dye laser pulses, controlling frequency doubled (5320 A) yttrium aluminum garnet ...
Observation of the formation of the 0-pi pulse
(American Physical Society, 1984-08-06)
We have measured with 0.5-psec resolution the reshaping of small-area 7-psec laser pulses to 0-pi pulses due to their passage through an optically thick sodium cell. The reshaped pulses have a picosecond oscillatory structure ...
Self-induced adiabatic rapid passage
(American Physical Society, 1975-09)
We show that, by virtue of the linewidth reduction provided by counter-propagating beams, it is possible to use the optical Stark shift to sweep a two-photon resonance through the sum frequency of the applied light while ...