Physicists Shed New Light on the “Invisible” Energy States of Molecules

A team of scientists at the University of Bath in the UK has discovered a method to use light particles to uncover the hidden energy states of molecules.

An international team of scientists, led by physicists from the University of Bath, has demonstrated a new optical phenomenon that could significantly impact various fields, including pharmaceutical science, security, forensics, environmental science, art conservation, and medicine.

Molecules rotate and vibrate in very specific ways. When light shines on them it bounces and scatters. For every million light particles (photons), a single one changes colour. This change is the Raman effect. Collecting many of these color-changing photons paints a picture of the energy states of molecules and identifies them.

Yet some molecular features (energy states) are invisible to the Raman effect. To reveal them and paint a more complete picture, ‘hyper-Raman’ is needed.

Hyper-Raman

The hyper-Raman effect is a more advanced phenomenon than simple Raman. It occurs when two photons impact the molecule simultaneously and then combine to create a single scattered DOI: 10.1038/s41566-024-01486-z

The study was funded by The Royal Society, the Leverhulme Trust, and the Engineering and Physical Science Research Council (EPSRC).