Clouds inspire new form of waveguiding

The research makes it possible to guide light waves around curved paths tunnelled through opaque materials that would normally scatter them in all directions.

According to the team, it could find applications in future generations of medical imaging technology, providing new ways for doctors to look inside the human body. It could also be adapted to guide heat instead of light, opening up new applications in thermal management for computing systems, and to confine particles like neutrons instead of light waves, which could find use in nuclear technologies.  

The new ‘waveguiding’ effect is said to be analogous to fibre optic cable, which carries light through its core by using total internal reflection. In fibre optics, the core is surrounded by a cladding material with a lower refractive index, which keeps the light moving along the core's length, allowing it to travel long distances with minimal loss.  

In the researchers’ new waveguiding mechanism, light is transported through a solid core of weakly scattering material, which is in turn encased in a material which scatters much more strongly. The contrast between the scattering properties of the materials confines the light to the core and enables it to be guided with unexpectedly high precision.