Light waves can now be governed

​New York: The researchers at the University of Buffalo have made a new discovery in the field of predictable reflection; a phenomenon where objects can either be transparent or opaque to different wavelengths.

The discovery works with materials that are periodic meaning they are made of repeating units. Crystals fall into this category as do certain parts of the wings of butterflies, whose periodic structure helps give them color by reflecting specific colours 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 Braggs law gives the angles for coherent and incoherent scattering from a crystal lattice has been a foundation for the new discovery. "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 Victor A Pogrebnyak, adjunct associate professor of electrical engineering at UB.

The Bloch wave resonance enables the blocking of a larger range of wavelengths simultaneously than previously known effects described by Bragg's law.

This discovery opens up new opportunities in photonics, nanoelectronics, optics and acoustics and many other areas of science and technology that exploit band gap wave phenomena for practical use.