Nanoparticles control light like road signs direct traffic

Image: Ella Maru Studio - Physicists at The Australian National University (ANU) have developed tiny translucent slides capable of producing two very different images depending on the direction in which light travels through them. As light passes through the slide, an image of Australia can be seen, but when you flip the slide and look again, an image of the Sydney Opera House is visible. The pair of images created is just one example of an untapped number of possibilities. The ability to produce two distinctly different images is possible thanks to the ANU scientists' ability to control the direction in which light can and can't travel at the nanoscale. The development could pave the way for new light-based devices that could lead to faster, cheaper and more reliable Internet. It could also serve as the foundation for many of the technologies of tomorrow. Developed in collaboration with colleagues from China, Germany and Singapore, the new technology uses nanoparticles, so small that about 12,000 of them can fit within a cross-section of a human hair.