University of Oxford physicists have successfully created the first-ever real-time, three-dimensional simulations of a ‘bizarre’ phenomenon where three high-energy lasers intersecting in an empty vacuum appear to generate a third laser light from complete darkness.
Although physicists have previously predicted this process, called vacuum four-wave mixing, the new simulations are the first to show the process actually occurring in three dimensions and under predicted vacuum conditions. If proven experimentally, the simulations could aid in the search for purely hypothetical particles, including axions and millicharged particles, which are also candidates for dark matter.
“This is not just an academic curiosity—it is a major step toward experimental confirmation of quantum effects that until now have been mostly theoretical,” explained University of Oxford Department of Physics Professor Peter Norreys, a co-author on the study detailing the team’s research.
Simulations Show Bizarre Phenomenon that Makes Light from Darkness
Physicists historically thought the quantum vacuum state was empty. However, quantum physics theorizes that the vacuum is filled with ‘virtual’ pairs of positrons and electrons. Scientists demonstrated a similar concept in 2022 when they produced an analog of particle-antiparticle pairs where nothing had previously existed.
One theory based on the idea suggests that, under the right conditions, electron-positron pairs could become polarized, causing photons to begin colliding with one another. According to a press release from the Oxford research team announcing their successful simulations, these photon-photon scattering cascades would generate light from darkness.
Hoping to simulate the conditions necessary to generate the theoretically predicted bizarre phenomenon, the team worked with the Instituto Superior Técnico in the University of Lisbon to design three ‘virtual’ high-energy laser beams. According to the theory of vacuum four-wave mixing, the combined electromagnetic field of three high-power laser pulses focused on the exact location should be enough to create the photon-photon scattering cascade, resulting in light from darkness.
After running several simulations on an advanced version of the OSIRIS simulation software package, explicitly designed to model the complex interactions between laser beams and matter or plasma, the team checked their results against the original vacuum four-wave mixing theory. According to the team’s statement, the theoretical predictions and the simulations matched, showing “a bizarre phenomenon predicted by quantum physics, where light appears to be generated from darkness.”
“By applying our model to a three-beam scattering experiment, we were able to capture the full range of quantum signatures, along with detailed insights into the interaction region and key time scales,” explained Zixin (Lily) Zhang, a doctoral student at Oxford’s Department of Physics and the study’s lead author. “Our computer program gives us a time-resolved, 3D window into quantum vacuum interactions that were previously out of reach.”
The research team says these results reveal several unknown insights into this bizarre phenomenon and show them how shifting the timing of the laser pulses can change the result. They will also provide critical data for scientists designing “precise, real-world” tests, including realistic laser shapes and laser-pulse timing.
“Having thoroughly benchmarked the simulation, we can now turn our attention to more complex and exploratory scenarios—including exotic laser beam structures and flying-focus pulses,” Zhang explained.
New High-Power Lasers Could Experimentally Confirm Simulations
While the Oxford team moves forward with more complex simulations, the wait for experimental proof of their ‘light from darkness’ simulations may be relatively short. According to the team’s statement, a new generation of ultra-powerful lasers is preparing to come online.
Some upcoming laser facilities that could have enough power to confirm the photon-photon scattering predicted by the vacuum four-wave mixing theory include the European ‘Extreme Light Infrastructure (ELI)’ project and the United Kingdom’s Vulcan 20-20. Officials building China’s Station for Extreme Light (SEL) and SHINE facilities claim they will also reach these high energies. Photon-photon scattering is one of three flagship missions selected for the University of Rochester’s OPAL dual-beam 25 PW laser facility.
Study co-author Professor Luis Silva from the Instituto Superior Tecnico, University of Lisbon, and a Visiting Professor in Physics at the University of Oxford, said these new facilities could confirm the team’s simulations and benefit from them when planning several upcoming experiments.
“A wide range of planned experiments at the most advanced laser facilities will be greatly assisted by our new computational method implemented in OSIRIS,” Silva said. “The combination of ultra-intense lasers, state-of-the-art detection, cutting-edge analytical and numerical modeling are the foundations for a new era in laser-matter interactions, which will open new horizons for fundamental physics.”
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.