Transfer of microwave radiation in sliding mode plasma waveguides

Guiding and amplification of microwave radiation in a plasma channel created in gas by intense ultraviolet laser pulse

“…Such a regime is based on the effect of total internal reflection of RF radiation at the boundary of the plasma, which is optically less dense medium than a non-ionized gas. Theoretical consideration of such a sliding-mode plasma waveguide was performed by Zvorykin et al (2010). The experimental realization (Zvorykin et al, 2012) of a 5 cm radius waveguide with an electron density of plasma walls n e~1 0 12 cm −3 created by the radiation of 70 ns KrF laser pulse provided the possibility to transport the microwave signal (λ = 8 mm) up to a length of 60 m, which is more than two orders of magnitude higher than the result obtained by Chateauneuf et al (2008).…”

Triggering and guiding electric discharge by a train of ultrashort UV pulses and a long UV pulse emitted by a hybrid Ti:Sapphire-KrF laser facility

“…There are triggering and diverting of lightning 1,2 , directing of microwave radiation to overcome its original divergence [3][4][5] , laser-driven acceleration and guiding of electrons 6 among them. In contrast to early experiments with CO 2 laser pulses of microsecond length 7 , where opacity of dense plasma produced via avalanche ionization limited the length and continuity of the channel, approaches based on the use of ultraviolet (UV) 1,2,8,9 or femtosecond 10,11 laser pulses can produce long-distance partially ionized tracks in air (or other gas) due to multiphoton ionization either with or without filamentation of radiation.…”

The interaction of polarized microwaves with planar arrays of femtosecond laser-produced plasma filaments in air

“…The radius of the waveguide must be ideally larger than the wavelength of the propagating radiation and the wall thickness larger than the skin depth. The wall of the waveguide may consist of uniform plasma generated by nanosecond ultraviolet laser pulses [1][2][3][4][5][6] or multiple plasma filaments generated by near infrared femtosecond pulses 7-12 arranged in a circular shape. There is a great interest in understanding in more detail the interaction of microwaves with plasma structures in order to eventually maintain the microwave propagation over long distances and with minimal losses, while minimizing the laser energy used to create the waveguide.…”

“…By creating a plasma cylindrical waveguide, a microwave signal could be transferred over distances up to several tens of meters. [1][2][3] The guiding mechanism is based on partial internal reflection at the air-plasma interface, which confines the microwave in the hollow core region. The radius of the waveguide must be ideally larger than the wavelength of the propagating radiation and the wall thickness larger than the skin depth.…”