Editing Wireless power transfer (section)

=== Atmospheric plasma channel coupling ===
{{See also|Electrolaser}}

In atmospheric plasma channel coupling, energy is transferred between two electrodes by electrical conduction through ionized air.<ref name="Nawaz">{{Cite journal |last1=Nawaz |first1=Suddiyas |title=Wireless Power Transmission |url=https://www.academia.edu/9539890 |website=Academia 2015 |access-date=31 December 2015}}</ref> When an electric field gradient exists between the two electrodes, exceeding 34 kilovolts per centimeter at sea level atmospheric pressure, an electric arc occurs.<ref name="Ray_2009">{{Cite book |title=An Introduction to High Voltage Engineering |last=Ray |first=Subir |publisher=PHI Learning |year=2009 |isbn=978-8120324176 |pages=19–21 |url=https://books.google.com/books?isbn=812032417X}}</ref> This atmospheric [[Electrical breakdown|dielectric breakdown]] results in the flow of electric current along a random trajectory through an ionized [[plasma channel]] between the two electrodes. An example of this is natural lightning, where one electrode is a virtual point in a cloud and the other is a point on Earth. Laser Induced Plasma Channel (LIPC) research is presently underway using ultrafast lasers to artificially promote development of the plasma channel through the air, directing the electric arc, and guiding the current across a specific path in a controllable manner.<ref>{{cite web |title=Electrolaser |website=WiseGeek website |publisher=Conjecture Corp. |year=2015 |url=http://www.wisegeek.com/what-is-an-electrolaser.htm |access-date=25 October 2015}}</ref> The laser energy reduces the atmospheric dielectric breakdown voltage and the air is made less insulating by superheating, which lowers the density (<math>p</math>) of the filament of air.<ref name="Scheller">{{cite journal |last1=Scheller |first1=Maik |last2=Born |first2=Norman |last3=Cheng |first3=Weibo |last4=Polynkin |first4=Pavel |year=2014 |title=Channeling the electrical breakdown of air by optically heated plasma filaments |journal=Optica |volume=1 |issue=2 |pages=125–128 |doi=10.1364/OPTICA.1.000125 |bibcode=2014Optic...1..125S |doi-access=free}}</ref>

This new process is being explored for use as a laser lightning rod and as a means to trigger lightning bolts from clouds for natural lightning channel studies,<ref name="Rakov">{{cite book |last1=Rakov |first1=Vladimir A. |last2=Uman |first2=Martin A. |title=Lightning: Physics and Effects |publisher=Cambridge Univ. Press |date=2003 |pages=296–298 |url=https://books.google.com/books?id=TuMa5lAa3RAC&q=laser&pg=PA296 |isbn=978-0521035415}}</ref> for artificial atmospheric propagation studies, as a substitute for conventional radio antennas,<ref name="Stahman_1964">{{cite web |last1=Stahmann |first1=J. R. |title=LASER TYPE ULTRA-VIOLET RADIATION FEASIBILITY FOR LIGHTNING AND ATMOSPHERIC PROPAGATION STUDIES |url=http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=AD0609217 |archive-url=https://web.archive.org/web/20160126215236/http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=AD0609217 |url-status=dead |archive-date=26 January 2016 |website=DEFENSE TECHNICAL INFORMATION CENTER OAI |publisher=LIGHTNING AND TRANSIENTS RESEARCH INST ST PAUL MN |access-date=16 January 2016 |date=Oct 1964}}</ref> for applications associated with electric welding and machining,<ref name="Lawrence">{{cite book |last1=Lawrence |first1=Jonathan R. |last2=Waugh |first2=D. |title=Laser Surface Engineering: Processes and Applications |publisher=Elsevier |date=2014 |pages=456–460 |url=https://books.google.com/books?id=n297AwAAQBAJ&q=%22laser+guided+discharge%22&pg=PA456 |isbn=978-1782420798}}</ref><ref name="Forestier">{{cite journal |last1=Forestier |first1=B. |last2=Houard |first2=A. |last3=Revel |first3=I. |last4=Durand |first4=M. |last5=André |first5=Y. B. |last6=Prade |first6=B. |last7=Jarnac |first7=A. |last8=Carbonnel |first8=J. |last9=Le Nevé |first9=M. |last10=de Miscault |first10=J. C. |last11=Esmiller |first11=B. |last12=Chapuis |first12=D. |last13=Mysyrowicz |first13=A. |title=Triggering, guiding and deviation of long air spark discharges with femtosecond laser filament |journal=AIP Advances |date=March 2012 |volume=2 |issue=1 |pages=012151 |doi=10.1063/1.3690961 |bibcode=2012AIPA....2a2151F |doi-access=free}}</ref> for diverting power from high-voltage capacitor discharges, for [[directed-energy weapon]] applications employing electrical conduction through a ground return path,<ref name="Giulietti">{{cite book |doi=10.1007/978-3-642-03825-9_6 |chapter=On Lightning Control Using Lasers |title=Progress in Ultrafast Intense Laser Science |series=Springer Series in Chemical Physics |year=2010 |last1=Kasparian |first1=Jérôme |last2=Wolf |first2=Jean-Pierre |volume=98 |pages=109–122 |isbn=978-3-642-03824-2}}</ref><ref name="Franklin">{{cite book |last1=Franklin |first1=Steve |title=Non-Lethal Weapon Handbook |publisher=Digital Services |date=2015 |pages=161–162 |url=http://www.rottys.eu/download-pdf-non-lethal-weapon-handbook-book-by-digital-services.pdf}}</ref><ref name="Quick_2012">{{cite web |last1=Quick |first1=Darren |title=U.S. Army weapon shoots lightning bolts down laser beams |url=http://www.gizmag.com/laser-induced-plasma-channel/23117/ |website=Gizmag |publisher=Gizmag Limited |access-date=16 January 2016 |date=28 June 2012}}</ref><ref name="Kaneshiro">{{cite web |last=Kaneshiro |first=Jason |title=Picatinny engineers set phasers to 'fry' |website=news Archives |publisher=US Army official website www.mil.gov |date=21 June 2012 |url=https://www.army.mil/article/82262/Picatinny_engineers_set_phasers_to__fry_/ |access-date=25 October 2015}}</ref> and [[Radio jamming|electronic jamming]].<ref name="Clerici">{{cite journal |last1=Clerici |first1=Matteo |last2=Hu |first2=Yi |last3=Lassonde |first3=Philippe |last4=Milián |first4=Carles |last5=Couairon |first5=Arnaud |last6=Christodoulides |first6=Demetrios N. |last7=Chen |first7=Zhigang |last8=Razzari |first8=Luca |last9=Vidal |first9=François |last10=Légaré |first10=François |last11=Faccio |first11=Daniele |last12=Morandotti |first12=Roberto |title=Laser-assisted guiding of electric discharges around objects |journal=Science Advances |date=June 2015 |volume=1 |issue=5 |pages=e1400111 |doi=10.1126/sciadv.1400111 |pmid=26601188 |pmc=4640611 |bibcode=2015SciA....1E0111C}}</ref>