6th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Sensing, Imaging, and Solar Energy
P.O. Box 10, Bellingham, WA 98227-0010, United States
出版者
SPIE
产权排序
1
摘要
Photoexcitation of biased semiconductor photoconductiveantennas by femtosecond pulses is the most common and convenient technique for generating strong terahertz (THz) pulses. In this paper, we use the three-dimensional (3D) finite-difference-time-domain (FDTD) to analyze electricfielddistributionof THz pulses in the near-field from a photoconductiveantenna. The simulation is based on solving Maxwell's equations and the carrier rate equations simultaneously on realistic dipole antenna structures. The 3D FDTD simulation gives detailed features of THz electricfielddistribution in and out of the antenna. It is found that the difference of near-fielddistribution between the substrate and free space is considerably large. The fieldsof the alternating-current dipole exhibit an unsymmetrical distribution and a large deviation from those calculated using the simple Hertzian dipole theory. The magnitude of THz field in and out of the substrate attenuates rapidly while it holds the line in the gap center. The high-frequency components of THz radiation emission come only from the dipole antenna, while the low-frequency components are from both the center electrodes and coplanar stripline waveguide. This work can be used to optimize the design ofantenna geometry and raise the radiation field power.
Sheng-Wu Zou,Tong-Yi Zhang. Electric field distribution characteristics of photoconductive antennas[C]. P.O. Box 10, Bellingham, WA 98227-0010, United States:SPIE,2012:84190A.
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