Novel Terahertz Photoconductive Antennas

Abstract

The photoconductive (PC) antenna is a key device for the recent terahertz (THz) photonics based on laser-pumped generation and detection of THz radiation. In this paper we report on two new types of PC antennas: the Schottky PC antenna and the multi-contacts PC antenna. The former one is able to detect THz radiation intensity without the time-delay scan and useful for applications where spectroscopic information is not important, such as the THz intensity imaging. The latter one is useful for the polarization sensitive THz spectroscopy, such as the THz ellipsometry. The characteristic features of these new types of PC antennas are studied by using a THz time-domain spectroscopy system.

Time-Domain Numerical Modeling of THz Photoconductive Antennas

“…For considering the effect of the dielectric lens 2.7 cm , the semi-analytical approaches of [48] and [49] are applied to the radiated electromagnetic field, derived through a near-to-far-field FDTD algorithm [50]. Also, the receiving antenna effect is taken into account as proposed in [51], and the received current waveform is evaluated by applying (39) where corresponds to the radiated electromagnetic field calculated by the FDTD procedure, and is the photoconductance of the receiving PCA, which has been taken as the waveform of transient photogeneration depicted in Fig. 8.…”

Efficient measurement of broadband terahertz optical activity

“…This method does not require specialized THz emitters or detectors, which is an advantage over experiments that use multi-contact photoconductive antennas to simultaneously detect two orthogonal THz polarizations. [16][17][18] We also show that our method is superior to time-domain THz methods that rely on the measurement of the THz field at two 19,20 or three 21 judiciously chosen analyzer angles, as well as frequency domain methods that make use of incoherent far-infrared light sources and intensity detectors, such as bolometers or Golay cells. 22,23 In our experiment, the only required input is linearly polarized light.…”

Time-domain numerical modeling of terahertz receivers based on photoconductive antennas

“…The convolution of the photoconductivity over the incident electric field highlights the most characteristic effect produced in the receiver by the incident electric field E THz t. This approach has been widely employed [35,[43][44][45][46], and the calculation is performed as follows:…”