CONTROLLING lightning with lasers
LARGE SCIENTIFIC PROJECT
Figure 4. 2D maps of the VHF sources emitted during a lightning event with the laser on( a) and without laser( b). The laser path is shown in red. Reproduced from [ 4 ]. CC BY 4.0
would need more statistics to be answered, and installation difficulties meant that we were unable to take advantage of a large proportion of the season ' s lightning events. Therefore, additional experimental campaigns would be necessary to qualitatively assess the guiding efficiency of the laser filaments.
Conclusion
The Laser lightning rod experiment demonstrated that a high-repetition rate terawatt laser could guide lightning over 60 m by forming plasma filaments in the air. For lightning protection applications, the next step is to increase the length and guiding efficiency of the laser filaments, for example by doubling the laser frequency to obtain more energetic photons. Another important topic in the control of lightning will consist in the demonstration of lightning triggering with lasers. This should require the formation of long-lived conductive plasma channels, but their formation over long distances remains a real challenge [ 5 ].
REFERENCES
[ 1 ] S. Uchida, Y. Shimada, H. Yasuda, et al., J. Opt. Technol. 66, 199( 1999)
[ 2 ] X. M. Zhao, J. C. Diels, C. Yi Wang and J. M. Elizondo, IEEE J. Quantum Electron. 31, 599( 1995)
[ 3 ] A. Mysyrowicz, J. P. Wolf, Photoniques 127, 32( 2024) [ 3 ] C. Herkommer, P. Krötz, R. Jung, et al. Opt. Express 28, 30164( 2020) [ 4 ] A. Houard, P. Walch, T. Produit, et al. Nat. Phot. 17, 231( 2023) [ 5 ] T. Produit, J. Kasparian, F. Rachidi et al. Rep. Prog. Phys. 87, 116401( 2024)
Photoniques 131 I www. photoniques. com 41