headshot of Uttam Manna

Uttam Manna

Uttam Manna is making new discoveries in understanding interactions between light and matter. His lab at Illinois State University is one of the first to detect a special configuration to contain light energy within tiny particles.

Manna, an assistant professor of physics, explores how light interacts with extremely small particles, called nanoparticles. A nanoparticle to a particle would be the size of a soccer ball in relation to the planet Earth.

“When light interacts with matter, fundamentally a number of things can happen,” said Manna, “The light could be reflected, absorbed, transmitted, or scattered.” Manna and his team of students discovered that—in some particles—the answer is none of the above. “The light is instead contained within the volume of the structures,” he said, “as such that the structures act like an energy reservoir.” This special configuration is known as “optical anapoles” in the scientific community.

Illustration of the concept that can confine energy within the volume of the nanospheres

Illustration of the concept that can confine energy within the volume of the nanospheres.

The groundbreaking work by Manna and his students is contributing to a collaboration with the scientists at Argonne National Laboratory, the University of Chicago, and Kobe University in Japan. They are the first to detect confinement of light within the volume of a nanoparticle, also known as optical anapoles in silicon nanospheres. The results are published in Physical Review Letters (PRL).

“This is truly outstanding work,” said Department of Physics Chair Daniel Holland. “Physical Review Letters is the most prestigious journal in physics, and this is the first experimental physics paper published in the journal based on work done at Illinois State.”

Scientists have contemplated the existence of such phenomenon to explain the existence of dark matter and stable atoms and electron configurations since the early 1900s, noted Manna. The experiments by Manna’s lab used a specially designed light, called radially polarized light. The results obtained from the current study could be useful in developing novel optical devices, such as nanolasers and metamaterials, he said.

Manna and his team are the recipients of a grant from National Science Foundation.