Light and matter seem to be two completely separate types of stuff, but an accumulating body of research is showing that the interaction between the two is more common than one might think. Look no further than the aurora borealis and the process of photosynthesis to see such examples, and there are plenty of fascinating new experiments showing new realms of possibility in light-matter interactions. Who would have thought, for instance, that nanofibres would twist and turn in response to the passage of light?
On the cutting edge of studying these interactions are the researchers of the Light-Matter Interactions Unit, of the Okinawa Institute of Science and Technology (沖縄科学技術大学院大学).
Above is an image of one of their more recent experiments, in which PhD sutdent Mary Frawley used optical nanofibers and lasers to trap tiny (red-blood-cell-sized) plastic balls on an ‘optical conveyor belt’.”
“Normally light will travel down an optical fiber all the way to the other end, but the optical nanofiber Nic Chormaic’s group uses is so narrow at one point that light leaks out, what physicists call an ‘evanescent field’. This leaky light first attracts and then propels the plastic balls along the optical fiber.”
They hope to collaborate with biologists at OIST to replace the plastic with real cells so as to sort mixtures of cells found in biological samples. They would then use this technology to detect trace levels of viruses or chemicals.
Read more about the interaction between light and matter on OIST’s website.