in 1999 using a combination of three lasers with kilojoule energy to form a 2-m-long plasma spark 7, 8, 9. A first attempt to trigger and guide natural lightning with lasers was made by Uchida et al. The idea of using a laser to trigger lightning was first suggested by Ball 6. However, it requires expendable rockets and wires, the falling debris of which presents a danger. If the small rocket is fired at the right moment when conditions for lightning are met, this method can initiate lightning with a success rate of up to 90% (ref. Rapidly inserting a wire into the strong electric fields near the ground below a thundercloud results in a field at the tip of the wire sufficiently enhanced to produce electrical breakdown. In contrast to the classical lightning rod, which is intended to be struck by lightning that approaches the protected structure, the rocket-and-wire technique is intended to trigger lightning artificially. It protects buildings and their immediate surroundings by providing a preferential strike point for the lightning and guiding its electric current safely to the ground.Ī method to initiate lightning discharges with a small rocket trailing a long, grounded conducting wire was demonstrated by Newman et al. The lightning rod, whose invention in the 18th century is attributed to Benjamin Franklin, consists of a pointed conducting mast connected to the ground. The most widely used external protection against direct lightning strikes is still the lightning rod, also known as Franklin rod or lightning conductor. 2) and lightning damages amount to billions of dollars every year 3. The documented number of lightning fatalities is well above 4,000 (ref. Based on satellite data, the total lightning flash rate worldwide-including cloud-to-ground and cloud lightning-is estimated to be between 40 and 120 flashes per second 1, causing considerable damage and casualties. Lightning has fascinated and terrified humankind since time immemorial. This work paves the way for new atmospheric applications of ultrashort lasers and represents an important step forward in the development of a laser based lightning protection for airports, launchpads or large infrastructures. Although this research field has been very active for more than 20 years, this is the first field-result that experimentally demonstrates lightning guided by lasers. The guiding of negative lightning leaders by laser filaments was corroborated in three other instances by very-high-frequency interferometric measurements, and the number of X-ray bursts detected during guided lightning events greatly increased. The guiding of an upward negative lightning leader over a distance of 50 m was recorded by two separate high-speed cameras.
An experimental campaign was conducted on the Säntis mountain in north-eastern Switzerland during the summer of 2021 with a high-repetition-rate terawatt laser.
We believe that this experimental breakthrough will lead to progress in lightning protection and lightning physics. Here we present the first demonstration that laser-induced filaments-formed in the sky by short and intense laser pulses-can guide lightning discharges over considerable distances.
It is therefore important to develop better protection methods in addition to the traditional Franklin rod. Lightning discharges between charged clouds and the Earth’s surface are responsible for considerable damages and casualties. Nature Photonics volume 17, pages 231–235 ( 2023) Cite this article
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