Scientists Control Light with 2-D Photonic Band Gap Material

Want to control light? Scientists have discovered a new way to do so. They've demonstrated the ability of two-dimensional disordered photonic band gap material to be a platform to control light in unprecedented ways. This could allow researchers to manipulate the flow and radiation of light by breaking away from the highly angular and constrained pathways for light. This, in turn, could help with the development of compact optical circuits for signal processing and telecommunications.

Photonic band gap materials help steer photons in the same way that semiconductors steer the flow of electrons in modern electronics. In order to do so, the materials block light of a certain energy so that it won't be able to propagate or exist in the material. While photonic band gap materials are rare in nature, they can be seen in the iridescent wings of some butterflies or on opals.

Scientists have long believed that a photonic band gap within constructed materials must rely on the reflection in layers of crystalline structures such as silicon crystals. But by using numerical simulations, the researchers predicted that it's possible to have photonic band gap in disordered structures.

That's when the researchers got to work. They started with a "point pattern" to design the disordered materials. This design was then converted into a computer file for three-dimension printing of the base structure, with precise holes and slots that guided the assembly of alumina rods and sheets.

In the end, they created a disorderly material that wasn't limited to particular rotational symmetry--like an orderly periodic pattern. This means that the disorderly material could be built to be isotropic or look the same in all directions. This allows the scientists to choose any kind of bending or curved passes to direct the light's flow.

"Scientifically, it's terrific to prove that a disordered structure can have a photonic band gap, for all polarizations in all directions," said Weining Man, the lead researcher, in a news release.

The findings could help create future materials. Applications could include new materials that could be employed for more efficient solar panels and illuminated displays. However, it will be a long time before we see any of these practical applications.

The findings are published in the journal Proceedings of the National Academy of Sciences.