Matter from a vacuum
Physicists have achieved a remarkable breakthrough in laser science, demonstrating for the first time a practical method to dramatically increase the power with which laser light can be emitted.
The new technique paves the way for the creation of the most intense light ever produced in a laboratory, enabling experiments to study the fundamental laws of physics involving the interaction of light with matter and, even more interestingly, the direct interaction of light with the quantum vacuum .
This last case involves those experiments that prove that a vacuum is never truly empty, but rather full of virtual particles that appear and disappear all the time .
These superlasers will make it much easier to interact with these virtual particles, including capturing them from their virtuality and transforming them into real particles, allowing us to see matter emerging from “nothing” .
“The discoveries we’ve made so far are fascinating, and it seems we’re only beginning to understand the rich and complex physics of this mechanism. Simulations suggest we may have created the most intense coherent light source ever. I hope we have the opportunity to […] confirm this, but also to take what we’ve learned to larger facilities where we can generate even brighter light,” said researcher Robin Timmis of the University of Oxford, UK.
[Image: Helen Towrie/Oxford]
Laser relativístico
In a typical laser, a feed beam is fired towards a pair of mirrors facing each other. The light is continuously reflected, receiving more and more energy from the external beam, until it exits through one of the mirrors, which has a slightly transparent structure.
The innovation achieved now consists of replacing the mirror with a cloud of electrically charged particles, a plasma cloud, which acts as a mirror that moves very quickly.
It’s like pointing a flashlight at a mirror moving towards you at enormous speed. The reflected light becomes compressed and more energetic, similar to how the pitch of a siren increases when an ambulance speeds past. In this case, the plasma mirror moves so fast that Einstein’s theory of relativity kicks in, amplifying the light to much higher energies – this effect is known as relativistic harmonic generation.
Until now, experiments in this area required colliding beams of high-energy particles with powerful lasers and then carefully translating the results between different perspectives.
This new method avoids that complexity. Because everything happens within the laser system itself, it becomes possible to observe the results directly, without the need for complex frame-by-frame conversions. This should greatly facilitate the interpretation of future experiments.
“This work is a combination of laser technology, plasma physics and ultrafast materials science, meticulously tuned to resolve a persistent discrepancy between theory and experiment that has frustrated the field for more than two decades,” said Professor Brendan Dromey of Belfast University.
Source: www.inovacaotecnologica.com.br
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