Influence of Gap Size on Intense THz Generation From ZnSe Interdigitated Large Aperture Photoconductive Antennas (October 2016)

Autor: Marc A. Gauthier, Safieddin Safavi-Naeini, S. Mohsen Raeis-Zadeh, Tsuneyuki Ozaki, Marie Kirouac-Turmel, M. Reid, Christian-Yves Cote, Xavier Ropagnol, Marcel Bouvier, X. Chai
Rok vydání: 2017
Předmět:
Zdroj: IEEE Journal of Selected Topics in Quantum Electronics. 23:1-8
ISSN: 1558-4542
1077-260X
DOI: 10.1109/jstqe.2017.2662658
Popis: We report on the effect of gap size on the generation of intense THz pulses emitted from ZnSe interdigitated large-aperture photoconductive antennas. The use of a relatively large gap size (460, 700, and 932 μ m) was found to slightly influence the radiated THz waveforms and the spectrum but strongly affects the scaling of the radiated THz electric field where stronger saturation appeared for smaller gap sizes, contrary to the behavior expected for operation in the THz field-screening regime. We attributed these variations to the effect of the relatively large capacitance of the antennas, which tends to limit the maximum radiated THz power, and which can be linked to space charge screening. The response of the high-voltage pulse was simulated as a function of the gap size and capacitance, revealing that these variations occur on a time scale faster than the THz pulse duration, thereby impacting the radiation emission characteristics.
Databáze: OpenAIRE