Light Mkhumbuza watched a beam that began with no spin at all change as it moved through free space. As it travelled forward, regions with spinning behaviour appeared and separated out, in an effect Mkhumbuza described as though the spin had been hidden before revealing itself.
The observation is at the centre of research by scientists at the University of East Anglia in the United Kingdom and the University of the Witwatersrand in Johannesburg, South Africa. Their results, published on October 13, 2026 in Light: Science & Applications, find that light can develop spinning and twisting patterns in empty space without special lenses, mirrors or materials.
For decades, creating and controlling these properties generally called for special materials, engineered surfaces or optical systems that strongly focus a beam.
Dr. Kayn Forbes, a researcher at the University of East Anglia’s School of Chemistry, Pharmacy and Pharmacology, said light can naturally develop spinning, twisted behaviour when it is prepared correctly.
The researchers describe the effect through topology, the mathematical study of features that stay the same when an object is stretched, bent or reshaped. A beam’s topological structure remains constant as its shape changes in travel, and this structure influences how its different regions develop.
The work points to a hidden geometric structure in light that can affect its behaviour in ways researchers had considered difficult to achieve. It challenges long-standing assumptions about the interaction between light’s different properties.
The spinning patterns are known as chirality. Chirality describes something that cannot be placed on top of its mirror image through ordinary rotation, and light can carry left- or right-handed rotational characteristics.
Dr. Isaac Nape of the University of the Witwatersrand said researchers can change a beam’s topology to set where and how chirality emerges. That makes the twisted character of light a controllable feature of the beam’s initial structure.
One example is an optical vortex, a light wave that twists around its direction of travel like a corkscrew. Each twist can carry information, giving such structures potential uses in high-speed data transmission, secure communications and optical sensors.
The researchers also identify possible uses in medical diagnostics and pharmaceuticals, where structured light could distinguish between left- and right-handed forms of biologically important molecules. Other potential applications include compact chemical sensors, higher-capacity optical communication systems and quantum technologies.
A related paper, titled ‘Correlation geometry and topology of structured optical beams’ and written by Jyrki Laatikainen and Olga Korotkova, was submitted on September 16, 2026 and last revised October 3, 2026.
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