| Abstract [eng] |
The aim of the work is to characterize the THz radiation intensity, spectrum and beam parameters of the emitting LT-GaAs photoconductive antenna with embedded contacts, as well as these with a simple coplanar THz antenna. In this work, using the terahertz time-domain spectroscopy stand, Lumerical device software package simulation, THz interferometry measurement stand, and THz beam measurement stand, the influence of terahertz photoconductive antennas contacts configurations on the radiated terahertz pulse and its parameters was investigated. Two antennas were tested- with contacts on surface and with recessed contacts in semiconductor. During the THz-TDS measurements, the terahertz pulse intensities of both antennas were measured at different added voltage values, and the spectrum was displayed after Fourier transformation. It was found that the spectrum of the antenna with recessed contacts is wider, and the intensity of the terahertz pulse is several times higher. This was explained by a more directional arrangement of the electric field lines between the additional contacts. After modeling the electric field of both antennas in the Lumerical device environment, a difference in the distribution of electric field lines due to different contact configurations was found. This study confirmed that electric field lines are more directional in the case of recessed contacts. Using THz interferometry stand, the intensity of the terahertz pulse was measured at different added voltages, autocorrelation was performed, and the spectrum was found after Fourier transformation. A terahertz pulse beam was measured using a beam measurement stand. It was observed that the spread of the terahertz pulse of the antenna with embedded contacts is lower. This is explained by a more directional movement of photocarriers between contacts, which was induced by a more directional electric field. |
