Finding paves the way for devices that switch quickly between transparency and opacity to specific forms of light
Imagine a device that is selectively transparent to various wavelengths of light at one moment, and opaque to them the next, following a minute adjustment.
Such a gatekeeper would enable powerful and unique capabilities in a wide range of electronic, optical and other applications, including those that rely on transistors or other components that switch on and off.
In a May 20 paper in the journal Physical Review Letters, researchers in the University at Buffalo School of Engineering and Applied Sciences report a discovery that brings us one step closer to this imagined future.
The finding has to do with materials that are periodic, which means that they’re made up of parts or units that repeat. Crystals fall into this category, as do certain parts of the wings of butterflies, whose periodic structure helps give them color by reflecting specific colors of light.
Scientists have known since the early 20th century that periodic materials have special qualities when it comes to light. Such materials can reflect light, as butterfly wings do, and if you understand the internal structure of a periodic material, you can use an equation called Bragg’s law to determine which wavelengths will pass through the material, and which will be blocked due to reflection.
The new UB study shows that a completely periodic material structure is not needed for this kind of predictable reflection to take place.