‘Gatekeeper’ material could act as optical switch

Describing such material as a ‘gatekeeper’, the team says applications could include electronic and optical devices, including those that rely on transistors or other components that switch on and off.

The structure of a periodic material comprises parts that repeat, such as crystals. Bragg’s Law will show which wavelengths will pass through and which will be blocked. However, the researchers say that a completely periodic material structure is not needed predictable reflection and add the effect not only applies to light waves, but also to a broad range of wave phenomena.

“We have shown that Bragg’s Law is a special case of a more generalised phenomenon that was discovered in this study and named as a Bloch wave resonance,” said researcher Victor Pogrebnyak. “This opens up new opportunities in photonics, nanoelectronics, optics and acoustics.”

“Electrons behave as waves that can also exhibit a Bloch resonance,” said Professor Edward Furlani, “which can be used as a powerful method to control currents in nanoelectronic circuits.”

Applications that could take advantage of this development include white light lasers and a new type of fast switching transistor.