Nano-architected material refracts light backward; an important step toward creating photonic circuits

A newly created material can be seen as a proof of principle that it can be seen regardless of the angle at which the light strikes the material.

This property means that the light's speed is negative across a portion of the spectrum at all angles.

Think of the way a straw in a glass of water appears shifted to the side or the way eyeglasses focus light as examples of howfraction is a common property in materials. Light can be shifted a few degrees to one side. The light is sent in an angle completely different from the one at which it entered the material. This has not been observed in nature, but it was thought to occur in materials constructed to have a specific structural pattern. Fabrication processes have caught up to theory to make a reality.

Julia R. Greer, Caltech's Ruben F. and Donna say negative refraction is crucial to the future of nanophotonics, which seeks to understand and manipulate the behavior of light when it interacts with materials or solid structures at the smallest possible scales. The paper was published in a journal.

The new material is achieved through a combination of organization at the microscale and the addition of a coating of a thin metal germanium film. For example, lightweight ceramics that spring back to their original shape, like a sponge, are examples of the unusual, often surprising properties of the materials created by Greer.

The new material looks like a lattice of hollow cubes under an electron microscope. The width of the beams that make up the cube is 100 times smaller than the width of a human hair. The lattice was made using a material that is easy to work with in 3D printing, and then coated with metal germanium.

The combination of the structure and the coating gives the lattice an unusual property, according to the corresponding author of the paper. While a graduate student in the lab of Greer, he conducted this research and is now a researcher at the Catalan Institute ofNanoscience and Nanotechnology in Spain. The research team zeroed in on the cube-lattice structure and material as the right combination through a computer modeling process.

The research team had to come up with a completely new method to get the coated evenly. It isn't easy to get germanium atoms from a disk of germanium that is bombarded with high-energy ion that blasted germanium atoms off of the disk and onto the surface of the lattice.

There are potential applications for the technology.

Gordon Moore, a life member of the Caltech Board of Trustees, predicted in 1965, that integrated circuits would get twice as complicated and half as expensive every two years. The scaling predicted by Moore's Law should end soon because of the fundamental limits on power and transistor density. The current work is a step towards demonstrating optical properties that would be required to enable 3D photonic circuits. Because light moves faster than electrons, 3D photonic circuits would be much faster than traditional ones.

The paper is titled "Dispersion mapping in 3-Dimensional Core" and is aShell photonic Crystal lattices capable of negative refraction in the mid-Infrared.

More information: Victoria F. Chernow et al, Dispersion Mapping in 3-Dimensional Core–Shell Photonic Crystal Lattices Capable of Negative Refraction in the Mid-Infrared, Nano Letters (2021). DOI: 10.1021/acs.nanolett.1c02851 Journal information: Nano Letters Citation: Nano-architected material refracts light backward; an important step toward creating photonic circuits (2022, January 28) retrieved 28 January 2022 from https://phys.org/news/2022-01-nano-architected-material-refracts-important-photonic.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.