Twisted laser light distinguishes mirror-image molecules by their fragment counts - Phys.org

What the report says

Phys.Org reported on July 26, 2026, that researchers have demonstrated a laser-based method for telling apart mirror-image molecules by measuring the charged fragments produced when the molecules are hit with specially structured light. The work involved teams from the Tata Institute of Fundamental Research, Indian Institute of Technology Bombay and Indian Institute of Technology Hyderabad, and was published in Science Advances.

The study focuses on chirality, a property in which molecules exist in left- and right-handed forms, known as enantiomers. These forms can appear nearly identical but may interact differently in biological and pharmaceutical settings. In experiments at TIFR Hyderabad, the researchers used ultrashort laser pulses whose spin and twist could be controlled, directing them at gaseous samples of R- and S-camphor, a standard chiral molecule.

According to the report, the laser interaction broke the camphor molecules into ions, which were then measured with a time-of-flight mass spectrometer. The key result was that fragment counts changed depending on both the molecule’s handedness and the twist of the light. That meant the two enantiomers could be distinguished through ion signals rather than through more demanding measurements such as electron angular distributions or tiny differences in optical absorption.

The reported approach matters because identifying the correct enantiomer is important in chemistry, biology and drug development. Phys.Org noted that testing isolated gas-phase molecules reduces interference from solvents or surfaces, offering a more direct view of how structured light interacts with molecular handedness. The findings suggest twisted laser beams could become a useful probe for chiral analysis, though further development would be needed before any broad practical use.