Reviewed by Lexie CornerJan 29 2025
In two recent studies published in Nature Communications and Science Advances, Antonio Ambrosio and his team at the Center for Nano Science and Technology (CNST) at IIT Milan introduced a new material for photonics and optoelectronics, along with a technique for manipulating light in the temporal dimension.
According to Albert Einstein's biography, the theory of relativity stemmed from his dream of riding a beam of light. From Newton to the present, scientists have been fascinated by light's physical properties, and mastering its characteristics has led to groundbreaking technologies like lasers, fiber optics, and quantum computers.
Antonio Ambrosio, Principal Investigator of the Vectorial Nano-Imaging Lab and a two-time European Research Council grantee, specializes in controlling light and exploring its fundamental properties, along with the potential applications of his research.
Ambrosio’s work presents both a novel material for photonics and optoelectronics and a technique to control light in the temporal dimension—an approach linked to the space-time concepts in Einstein’s general relativity.
The first study is built on a forward-thinking idea: If a material could direct and alter the physical properties of light while behaving like a fluid that retains its integrity, it could enable advancements in quantum technologies, telecommunications, super-resolution optical microscopes, and even solar energy applications.
Depending on how an object interacts with light, it could appear vividly colored or nearly invisible. By studying a crystal composed of molybdenum, chlorine, and oxygen atoms (MoOCl₂), Ambrosio and his team demonstrated that visible light could be manipulated in this way.
The findings, published in Nature Communications, open new possibilities in nanophotonics, a field that uses light-matter interactions to uncover novel, highly controllable physical phenomena at the nanoscale.
A key breakthrough is the discovery that visible light can be confined and transported by ultra-thin crystal flakes—just a few billionths of a meter thick—without relying on traditional diffraction methods to retain the light within the material.
This effect is mediated by plasmonic polaritons, hybrid waves of matter and radiation typically found in metals. Depending on how the material interacts with light, its optical properties change—acting like a metal in one direction and an insulator or dielectric medium in the perpendicular direction.
The second study, published in Science Advances, presents a technique for investigating and manipulating light on incredibly short time scales—femtoseconds, or one-millionth of a billionth of a second. This method influences light's spatial properties, such as shape, by acting on its temporal dimension without relying on external forces.
The technique exploits the natural relationship between an electromagnetic wave’s temporal frequencies and its angular momentum—the property that dictates how energy flow rotates in space.
Ambrosio’s team introduced rapid modulations within the wave, generating impulse-like variations that altered its spatial and temporal distribution. This allowed them to achieve unprecedented effects, such as spiral trajectories and light self-acceleration.
This approach removes the need for external forces and enables fast, precise control of light. It has potential applications in manipulating nano- and microstructures—key elements in condensed matter physics—or advancing ultrafast spectroscopy.
Journal Reference:
Piccardo, M., et al. (2023) Broadband control of topological–spectral correlations in space–time beams. Nature Photonics. doi.org/10.1038/s41566-023-01223-y.