Carrier dynamics in ion-implanted GaAs studied by simulation and observation of terahertz emission

Low-Temperature MBE Grown GaAs for Pulsed THz Radiation Applications

The coherent generation and detection of terahertz (THz) radiation using ultrashort laser pulses and photoconductive antennae have been intensively studied during the last decade. The best results were achieved when low-temperature MBE grown GaAs (LTG GaAs) or ion-implanted GaAs layers were used as a basis for THz emitters and detectors. The ultimate performance of these devices depends on carr...

Carrier dynamics in low-temperature grown GaAs studied by THz emission spectroscopy

Excitation-density-dependent generation of broadband terahertz radiation in an asymmetrically excited photoconductive antenna.

The generation of terahertz (THz) transients in photoconductive emitters has been studied by varying the spatial extent and density of the optically excited photocarriers in asymmetrically excited, biased low-temperature-grown GaAs antenna structures. We find a pronounced dependence of the THz pulse intensity and broadband (>6.0 THz) spectral distribution on the pump excitation density and simu...

Generation and characterization of terahertz pulse trains from biased, large-aperture photoconductors.

The saturation properties of terahertz emission from biased, large-aperture photoconductors excited by trains of amplified femtosecond optical pulses are presented. A direct comparison is made of the multiple-pulse saturation properties of terahertz emission from semi-insulating GaAs and low-temperature-grown GaAs emitters with different carrier lifetimes. When the carrier lifetime is less than...

Terahertz Emission From Magneto-plasma Oscillations in Semiconductors

Ultrafast terahertz spectroscopy can be used to probe charge and spin dynamics in semiconductors. We have studied THz emission from bulk InAs and GaAs and from GaAs/AlGaAs quantum wells as a function of magnetic field. Ultrashort pulses of THz radiation were produced at semiconductor surfaces by photoexcitation with a femtosecond TiSapphire laser, and we recorded the THz emission spectrum and t...