Detection of terahertz radiation with low-temperature-grown GaAs-based photoconductive antenna using 1.55 mm probe
نویسندگان
چکیده
THz radiation is detected by a low-temperature-grown GaAs ~LT-GaAs! photoconductive antenna probed with a 1.55 mm probe laser. The detection efficiency is found to be approximately 10% of that obtained with a 780 nm probe. From the nonquadratic dependence of photoconductivity on laser intensity, two-step photoabsorption mediated by midgap states in LT-GaAs is suggested, instead of the two-photon absorption, as the primary process for the photoconductivity. © 2000 American Institute of Physics. @S0003-6951~00!01335-8#
منابع مشابه
Emission characteristics of photoconductive antennas based on low-temperature-grown GaAs and semi-insulating GaAs.
Terahertz radiation was generated with several designs of photoconductive antennas (three dipoles, a bow tie, and a coplanar strip line) fabricated on low-temperature-grown (LT) GaAs and semi-insulating (SI) GaAs, and the emission properties of the photoconductive antennas were compared with each other. The radiation spectrum of each antenna was characterized with the photoconductive sampling t...
متن کاملLow-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...
متن کاملExcitation-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...
متن کاملOn-Chip Picosecond Pulse Detection and Generation Using Graphene Photoconductive Switches
We report on the use of graphene for room temperature on-chip detection and generation of pulsed terahertz (THz) frequency radiation, exploiting the fast carrier dynamics of light-generated hot carriers, and compare our results with conventional low-temperature-grown gallium arsenide (LT-GaAs) photoconductive (PC) switches. Coupling of picosecond-duration pulses from a biased graphene PC switch...
متن کاملDetection of up to 20 THz with a low-temperature-grown GaAs photoconductive antenna gated with 15 fs light pulses
The generation and detection of terahertz ~THz! radiation using ultrashort optical pulses has been intensively studied during the last decade. The pulse width of commercially available mode-locked Ti:sapphire lasers is approaching 10 fs. With such ultrashort pulses, a wider detection bandwidth is expected to be possible. Coherent detection of THz radiation based on a photoconductive ~PC! antenn...
متن کامل