Simulation of photoconductive antennas for terahertz radiation (original) (raw)

Numerical Simulations of THz Photoconductive Antenna

2019

Terahertz (THz) (0.1 – 10 THz) region of the electromagnetic spectrum spans the frequency range between the mid-infrared and the millimetre range. THz technology has generated a lot of interest recently due to its potential applications as a tomographic imaging and material spectroscopic characterization technique in a wide range of industry sectors including aerospace industry, wood products industry, the pharmaceutical industry, art conservation and semiconductor industry. There have been significant advances in the development of THz sources and detectors. The radiated THz power from these devices, however, is very low, and they are very inefficient. Hence, there are still a lot of continued interests in developing more powerful and compact THz sources as this will enable new applications of this electromagnetic spectrum. In this thesis, a novel photoconductive antenna with an embedded electrode structure had been proposed. Formulated equations had been used with COMSOL Multiphys...

Influence of Substrate Material on Radiation Characteristics of THz Photoconductive Emitters

International Journal of Antennas and Propagation, 2015

We present in this paper spectral and spatial characteristics of terahertz emission from standard dipole antenna structures used as emitters depending on the substrate material. All antenna structures were lithographically fabricated on low-temperature (LT) grown, few-micrometers-thick gallium arsenide (GaAs) layers. To investigate the effect of the substrate material on the radiation pattern of terahertz beams, either semi-insulating gallium arsenide or high-resistivity silicon substrate wafers have been used. As detector a standard 40 µm long dipole antenna on a semi-insulating GaAs substrate with a low-temperature grown gallium arsenide layer on it has been employed; this configuration allows for broadband detection and is still efficient enough for the characterization purpose. Strong dependence of the radiation pattern on the substrate used for the terahertz source is demonstrated. The measured patterns and differences between the two cases of substrates are well explained by m...

THz generation using 800 to 1550 nm excitation of photoconductors

2009

We demonstrate the efficient generation of terahertz (THz) radiation from Fe-doped InGaAs-based photoconductive antennas. We present time-domain data showing generation of pulsed THz radiation from antennas fabricated on two different wafers, optimized to maximize the near-infrared-to-THz conversion efficiency. Detection was performed using both (110) ZnTe and GaP crystals, with pump and probe wavelengths being adjusted from 800 nm to 1550 nm using a cavity-tuned OPO pumped by a pulsed near-infrared Ti:Sapphire laser.