Could we one day control the path of lightning?
Credit: © domeozzy / Fotolia
Lightning dart across the sky in a
flash. And even though we can use lightning rods to increase the
probability of it striking at a specific location, its exact path
remains unpredictable. At a smaller scale, discharges between two
electrodes behave in the same manner, streaking through space to create
electric arcs where only the start and end points are fixed. How then
can we control the current so that it follows a predetermined path?
Professor Roberto Morandotti and his colleagues have discovered a way to
guide electric discharges--and even steer them around
obstacles--through the clever use of lasers. This scientific
breakthrough was published on June 19, 2015, in Science Advances.
Using the Advanced Laser Light Source (ALLS) facility, researchers
from the INRS Énergie Matériaux Télécommunications research centre
tackled this challenge, which had previously been the subject of
intensive research, particularly in the 1970s.
Electric arcs have long been used in such technologies as combustion
engines, pollution control applications, lighting, machining and
micromachining. Potential applications could multiply with the ability
to precisely control the path they take. A first step in this direction
has been made and research into the new possibilities and parameters for
guiding electric arcs promises to spark researchers' creativity.
Recent scientific and technical advances, as well as the ingenuity of
Professor Morandotti's team (particularly researcher Matteo Clerici, a
postdoctoral fellow with the research group at the time of the
experiments), set the stage for this spectacular demonstration, where we
see an electric charge follow a smooth path along a straight or
parabolic trajectory.
Experimental figures show how different shaped lasers give discharges
distinct properties and trajectories. By combining beams, it is even
possible to achieve an S-shaped trajectory, with all other kinds of
trajectory achievable in principle.
In his bold quest for knowledge, Professor Morandotti wanted to
determine whether the self-healing properties of certain shapes of laser
beams (such as Airy and Bessel beams) could be put to use in these new
experiments. This attribute means that a laser beam whose intensity peak
is blocked by an obstacle can reconstruct itself once past the object.
Professor Morandotti's team placed an object between the two electrodes
and observed that the discharge leapt over the obstacle, without
damaging it, and returned to its laser guide on the other side.
"Our fascination with lightning and electric arcs aside, this
scientific discovery holds out significant potential and opens up new
fields of research," said Yves Bégin, vice dean of research and academic
affairs at INRS. "This spectacular proof of concept, which was
conducted over a distance of a few centimetres, required the high-power
lasers, state-of-the-art facilities, and extraordinary research
environment that our professors helped to create at INRS. Being able to
work in such cutting-edge labs enables our students and postdoctoral
fellows to embark on the path of scientific discovery even while still
in school."
Story Source:
The above post is reprinted from
materials provided by
Institut national de la recherche scientifique - INRS. The original item was written by Stéphanie Thibault.
Note: Materials may be edited for content and length.