Light and physics: an interview with Mauro Nisoli to mark International Day of Light

16 May marks International Day of Light, proclaimed by UNESCO to highlight the importance of light in our daily lives and its applications in science.

To mark this occasion, we interviewed Mauro Nisoli, Full Professor, Head of the Department of Physics and Director of the Attosecond Research Center, who explains what light means for scientific research and the role it plays in physics today.

Why is light so important and what role does it play in physics?

Light is fundamental because it is one of the main ways in which we understand the world. Thanks to light, we observe our surroundings, study matter, gather information from the universe and measure physical phenomena with the highest precision. It has played a decisive role in the history of physics: understanding the nature of light led to the development of electromagnetism, relativity and quantum mechanics. Even today, light is both a subject of study and a powerful tool for exploring reality.

Can discoveries made in physics laboratories be translated into practical applications for society?

Basic research often stems from a desire to understand a phenomenon, without any immediate application already in mind. Yet many of the technologies we use on a daily basis today stem precisely from discoveries made in physics laboratories. Think of lasers, optical fibres, medical imaging, sensors, photovoltaic panels or telecommunications technologies.

The transition from fundamental research to practical applications is not always immediate, but it is essential: an understanding of physical principles leads to the development of tools capable of improving health, energy, the environment, safety and communication.

What role do lasers, photonics and optical technologies play in contemporary research?

Lasers, photonics and optical technologies are now central to a vast number of research fields. Lasers enable the production of highly controlled, intense and precise light, useful for measuring, manipulating and analysing matter. Photonics studies and utilises light to transmit, process and collect information, with applications ranging from ultra-fast communications to quantum technologies.

Optical techniques are also indispensable in medicine, microscopy, astronomy, materials science and environmental monitoring. In many cases, light allows us to observe phenomena that would otherwise remain invisible.

In your view, what will be the next major scientific challenge related to light that we will see addressed over the next ten years?

Over the next ten years, one of the major challenges will be to control light and matter with ever-greater precision, right down to the microscopic and quantum scales. This could pave the way for new, extremely sensitive sensors, more secure communications, quantum computers, more advanced diagnostic tools and more efficient energy technologies.

Another major challenge will be to make these innovations sustainable, accessible and beneficial to society. Light will not merely be a tool for observing the world, but will increasingly become a means of altering, protecting and better understanding it.

Is there a message you would like to leave for the students who are taking their first steps in physics and research today?

To those starting out in physics today, I would say never lose your curiosity. Research stems from questions, even those that seem simple or naive. Studying physics means learning to observe carefully, to reason rigorously and not to settle for superficial explanations.

It is a demanding but also creative journey that helps us understand the world and build useful tools for the future. In this sense, light is a perfect symbol of research: it illuminates what we do not yet know and invites us to look beyond.