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The authors present a simple add on for multicycle, multimJ Ti:sapphire-based amplifier systems to efficiently generate 9.5 fs pulses with 1.8 mJ. Filamentary propagation yields spectrally broadened pulses carrying an unexpected large group-delay dispersion of -500 fs2 which allows linear propagation of the few-cycle pulses towards target areas without need of any sophisticated dispersion control. Pulse compression could easily be achieved by transmission through a combination of different glass substrates. The pulse wave front, the low energy fluctuations, and the good temporal contrast make this source well suited for relativistic laser-solid experiments with intense few-cycle pulses at kilohertz repetition rate. [ABSTRACT FROM AUTHOR]

Electrical sampling with a temporal resolution of less than 500 fs has been achieved using coplanar transmission lines on electro-optic substrates. The improved performance over the previously demonstrated balanced stripline is due to the reduced dimensions, i.e., distance between the electrodes and width of the electrodes, achievable with photolithographic technique. By further reducing the line dimensions to 10-20-μm range, this technique makes the temporal resolution of electrical waveforms in the range of 100 fs possible. [ABSTRACT FROM AUTHOR]

Picosecond bistable operation has been experimentally observed for the first time in a double-barrier resonant tunneling diode. A rise time of 2 ps was measured using the electro-optic sampling technique; this is the fastest switching event yet observed for an electronic device. This time domain measurement adds necessary information to the understanding of the transport mechanisms in the resonant tunneling diode and is consistent with switching time limitations computed for the device. It also demonstrates that appropriately designed double-barrier quantum well diodes have a response time comparable to that of the fastest all-optical logic elements, and that they may be very useful in high-speed logic applications. [ABSTRACT FROM AUTHOR]

Dramatic bandwidth enhancement has been achieved in a GaAs traveling-wave electro-optic phase modulator by the addition of a GaAs superstrate to suppress both velocity mismatch and electrical dispersion. [ABSTRACT FROM AUTHOR]

A novel material deposited by molecular beam epitaxy at low substrate temperatures using Ga and As4 beam fluxes has been used as the active layer for a high-speed photoconductive optoelectronic switch. The high-speed photoconductive performance of the material was assessed by fabricating two devices: an Auston switch and a photoconductive-gap switch with a coplanar transmission line. In a coplanar transmission line configuration, the speed of response is 1.6 ps (full width at half maximum) and the response is 10 to 100 times greater than that of conventional photoconductive switches. Since the material is compatible with GaAs discrete device and integrated circuit technologies, this photoconductive switch may find extensive applications for high-speed device and circuit testing. [ABSTRACT FROM AUTHOR]

We have performed time-resolved photoluminescence on GaAs/AlxGa1-xAs single quantum well structures with an electric field applied perpendicular to the well plane. The quantum wells are coupled to the GaAs continuum through a thin barrier; the escape time of the electrons in the well was measured by time-resolved photoluminescence. The dependence of the decay time on applied bias was found to agree very well with a simple semiclassical model. [ABSTRACT FROM AUTHOR]

Examines the laser-induced breakdown in fused silica with laser pulse widths from 7 nanosecond to 150 femtosecond. Measurement of the impact ionization coefficient; Role of photoionization in ultrashort pulses breakdown; Dominance of the avalanche ionization mechanism over the entire pulse-width range.