By Ashley Yeager
Harry Potter's invisibility cloak is not exactly what scientists have in mind for their light tricks. Credit: Warner Brothers.
The way we understand light is largely based on how we see it. To our eyes, light is like a stream of particles.
Scientists usually study these particle streams by measuring their wavelengths and how they interact with objects. But over the last decade, researchers have begun to realize that light particles can interact with objects within wavelengths too.
Now, scientists are looking inside wavelengths to control and manipulate light, which is transforming the traditional field of optics, according to Duke engineer David Smith and his colleagues.
They describe the changes to the field of optics in a review article appearing online Aug. 2 in Science, and they describe how, at a tenth or even a hundredth of the wavelength of visible light, the classic picture of how we see breaks down.
In this regime, streams of light particles can bend away from an object, essentially tricking the eye into thinking the object is not there. As a result, scientists can no longer think of light in terms of particle streams. Instead, they must think of it as a manipulation of electric and magnetic field lines.
Thinking of light this way, Smith and other scientists are beginning to understand how they can hide one object within another and even harvest energy. The new understanding “will be the design tool of choice” as scientists continue to play with the forces between electrically charged particles, the authors argue.
Citation:
“Transformation Optics and Subwavelength Control of Light.” Pendry, J., et. al. 2012. Science 337: 549-552.
DOI: 10.1126/science.1220600