7th Asia-Pacific Conference on Plasma Physics, 12-17 Nov, 2023 at Port Messe Nagoya

Laser-guided lightning using kHz filamentation at 1030 nm
A. Houard1, P. Walch1, T. Produit2, V. Moreno2, B. Mahieu1, A. Sunjerga3, C. Herkommer4, A.
Mostajabi3, U. Andral2, Y.-B. André1, M. Lozano1, L. Bizet1, M. C. Schroeder2, G. Schimmel2, M.
Moret2, O. Maurice5, B. Esmiller5, K. Michel4, W. Haas6, T. Metzger4, M. Rubinstein7, F. Rachidi3,V. Cooray8, A. Mysyrowicz1, J. Kasparian2,9, J.-P. Wolf2
1Laboratoire d’Optique Appliquée – ENSTA Paris, Ecole Polytechnique, CNRS, IP Paris, France
2
Groupe de Physique Appliquée, Université de Genève, Switzerland
3
EMC Laboratory, Electrical Engineering Institute, EPFL, Switzerland
4
TRUMPF Scientific Lasers GmbH + Co. KG, Germany
5
ArianeGroup, France
6
Swisscom Broadcast AG, Switzerland
7
School of Management and Engineering Vaud, HES-SO, Switzerland
8
Department of Electrical Engineering, Uppsala University, Sweden
9
Institute for Environmental Sciences, Université de Genève, Switzerlande-mail (speaker): aurelien.houard@polytechnique.edu

Controlling lightning is a long-time dream of mankind.
Along with the rapid evolution of laser technologies, theidea to develop lightning protection based on
filamentation of high-power ultrashort-pulse lasers
emerged in the 1990s [1]. The goal of the Laser Lightning
Rod (LLR) project that started in 2017 was to investigate
a new type of lightning protection based on the use ofupward lightning discharges initiated through a highrepetition-rate terawatt laser [2]. To that end, a high-power
laser was developed by Trumpf scientific with pulse
energy in the Joule-range, 1 ps pulse duration, and arepetition rate of 1 kHz [3]. This CPA laser system is basedon Yb-YAG thin-disk technology allowing amplification
at very high average power at a wavelength of 1030 nm.
The long-range propagation of this high energy kHz
laser in the multiple filamentation regime and its ability tocontrol high-voltage discharges were first studied in a120-m long horizontal corridor. Then, a field campaign
was carried out to assess the laser ability to trigger orguide upward lightning discharges from a tall structure.
The lightning experimental station at the Säntis mountainin Northeastern Switzerland was chosen for thisexperiment. Located at an altitude of 2 500 meters, thisunique site is fully instrumented for the study of lightning
phenomena.
The guiding of an upward negative lightning leader
over a distance of 50 m was recorded by two separate
high-speed cameras. The guiding of negative lightning
leaders by laser filaments was corroborated in three otherinstances by VHF interferometric measurements, and thenumber of X-ray bursts detected during guided lightning
events was significantly increased [4]. While this research
field has been very active for more than 20 years withmany research groups around the world working toachieve this goal, this result demonstrates for the first timethat lightning can be guided by lasers, which may lead tothe development of a laser lightning rod.

Figure 1. Photography of the LLR experiment on Mount Säntis
in July 2021. @TRUMPF/Martin Stollberg

References[1] X.M. Zhao, J.C. Diels, C.Y. Wang, and J.M.
Elizondo, “Femtosecond ultraviolet laser pulse induced
lightning discharges in gases,” IEEE J. Quantum
Electron. 31, 599 (1995)[2] T. Produit et al., "The laser lightning rod project,Eur". Phys. J. Appl. Phys. 92, 30501 (2020)[3] C. Herkommer et al., "Ultrafast thin-disk multipass
amplifier with 720 mJ operating at kilohertz repetition
rate for applications in atmospheric research", Opt.
Express 28, 30164–30173 (2020)[4] A. Houard, et al. “Laser-guided lightning”, Nat.
Photon. 17, 231 (2023)