Detection of Surface Waves During Femtosecond Filamentation

Autor:	Garrett, Travis, Janicek, Anna, Fayard II, J. Todd, Elle, Jennifer
Rok vydání:	2024
Předmět:	Physics - Plasma Physics Physics - Computational Physics Physics - Optics
Druh dokumentu:	Working Paper
Popis:	Ultrashort pulsed lasers (USPL) can produce thin columns of plasma in air via femtosecond filamentation, and these plasmas have been found to generate broadband TeraHertz (THz) and Radio Frequency (RF) radiation. A recent theory argues that the currents driven at the boundary of the plasma excite a Surface Plasmon Polariton (SPP) surface wave (in particular a Sommerfeld-Goubau wave given the cylindrical symmetry), which proceeds to detach from the end of the plasma to become the RF pulse. We have performed near-field measurements of these plasmas with a D-dot probe, and find an excellent agreement with this theory. The radial field dependence is precisely fit by a Hankel function, with an outer length scale in agreement with plasma conductivity and radius, and a measured longitudinal drift in frequency maxima closely matches both SPP simulations and analytic expectations. Comment: 8 pages, 7 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2412.05472 Zobrazit plný text záznamu View this record from Arxiv