An Efficient Nano-Sized Optical Computer Processes Complex Data | Research & Technology | March 2022

An Efficient Nano-Sized Optical Computer Processes Complex Data |  Research & Technology |  March 2022

NEW YORK, March 14, 2022 – A research team led by Andrea Alù of the City University of New York (CUNY) and Heedong Goh of the CUNY Graduate Center’s Advanced Science Research Center (CUNY ASRC) has developed a design for a nano-sized , a wave-based computer that is capable of solving advanced mathematical calculations at the speed of light. The advancement stems from researchers investigating how nanomaterials interact with light waves, which could accelerate the development of small but powerful, low-energy optical computers for practical use.

Scientists have shown that more efficient computation can be achieved through optical devices that use interactions between metamaterials and light waves to apply mathematical operations to incident waves. Although these computers can perform calculations faster and with less power than conventional computers, they require large footprints and precise, large-area manufacturing of components. Due to their size, they are difficult to scale and integrate into computer networks.

“The growing energy demands of large data centers and the inefficiencies of current IT architectures have become a real challenge for our society,” Alù said.

The researchers’ device addresses the growing need for scalable computers that can quickly solve a myriad of complex problems. While previous designs used large-area metamaterials that limited their scalability, the CUNY team designed these structures at the nanoscale, to support scalability and practical application in their computer.

To build the computer, the team used silicon that is formed into a nanometer-sized geometric shape optimized to solve a specific problem. When the computer is interrogated with light waves carrying an arbitrary input signal, it encodes the corresponding solution to the mathematical problem into the scattered light waves. The solution is calculated at the speed of light, with minimal power consumption.

The non-local response of the compact light diffuser is designed to transmit selected operations on arbitrary incident waves, and even to solve integro-differential equations. Solutions appear in scattered fields. The absence of strongly resonant phenomena makes the response robust, and the small size of the computer allows process cascade.

“The very small size of these nanoscale optical computers is particularly attractive for scalability, as multiple nanostructures can be combined and connected together by light scattering to achieve complex nanoscale computer networks,” said Goh.

To date, optical computers that perform ultrafast calculations based on interactions between light and metamaterials are too large for practical application.

A CUNY team has presented a design for a nanoscale optical computer capable of performing advanced mathematical calculations at the speed of light. In design, waves scattered from a nanoscale object encode the solution of a complex mathematical problem when queried by suitable input signals. Courtesy of Heedong Goh.

“Our work demonstrates that it is possible to design a nanoscale object that can efficiently interact with light to solve complex mathematical problems with unprecedented speeds and near-zero energy demands,” Alù said.

The nanometer-sized optical analog computer is a step towards the realization of ultra-compact, low-power computers capable of performing complex mathematical calculations.

“This discovery is promising because it offers a practical path to create a new generation of ultra-fast, ultra-compact and highly energy-efficient nanoscale optical computers and other nanophotonic technologies that can be used for classical and quantum,” Goh said.

The research has been published in Physical examination letters (