“An international team of physicists has achieved a significant advance in laser science, demonstrating for the first time a practical route to dramatically boosting the intensity of high-power laser light.

The results, published in Nature, could unlock the route towards creating the most intense light ever produced in a laboratory, opening the door to experiments that probe the fundamental laws of physics by directly interacting light with the quantum vacuum…

Using the Gemini laser at the CLF, the team created extremely bright ultraviolet light through an unusual process. In simple terms, they fired an intense laser at a cloud of charged particles (a plasma), causing it to behave like a rapidly moving mirror.

This can be likened to shining a flashlight at a mirror that is rushing toward you at enormous speed. The reflected light becomes compressed and more energetic—similar to how the pitch of a siren rises as an ambulance speeds past.

In this case, the ‘mirror’ is moving so fast that Einstein’s theory of relativity comes into play, boosting the light to much higher energies. This effect is known as relativistic harmonic generation.

The team also demonstrated a way to concentrate this light even further, in what they call a Coherent Harmonic Focus.

An analogy is using a magnifying glass to focus sunlight onto a tiny point so intense it can burn paper. Here, instead of sunlight, many different colors (wavelengths) of laser light are brought together and focused into an extremely small region, creating a huge concentration of energy.

This advance could eventually allow scientists to explore one of the most extreme frontiers of physics: how light and matter interact at the most fundamental level, described by a theory called quantum electrodynamics (QED).”

From Nature.