Illuminating electronics: Researchers construct all-optical pocket calculator

July 30, 2018

Our daily lives rely on electronic processors, which perform the basic arithmetic, logical, and control operations that make devices from mobile phones to smart TVs possible. Current technologies are, however, approaching their limits and researchers around the world are looking to enable the next generation of computing.

In their paper now published in Science Advances, an interdisciplinary team of researchers at Aalto University show how a new type of nanowire-based nanostructure enables light to perform logic functions, allowing simple addition and subtraction operations. The study, the first to demonstrate nanoscale all-optical logic circuits, provides a vital step in the journey towards true optical computing.

'We're able to perform binary number calculations and show, for instance, how this nanostructure can carry out these functions just like a simple pocket calculator--except that instead of using electricity, the nanostructure uses only light in its operation,' says Dr. Henri Jussila, who completed a post-doc at the university.

To build the nanostructure, the team took a novel approach to assemble two different semiconductor nanowires, indium phosphide and aluminum gallium arsenide. The nanowires, both shorter and exponentially thinner than the diameter of a human hair, have a unique one-dimensional structure, which allows them to function like nanosized antennas for light.

'We used a simple combing technique, similar to how people comb their hair in the morning, to assemble these nanostructures,' explains Jussila.

With this mechanical combing method, nanowires can be aligned in any specific direction, which differs from the as-fabricated randomly aligned nanowires typically used. Repetition, however, is key to getting the antennas into ideal alignment.

'Repeating the combing method allows us to build integrated devices of nanostructures in which two different types of nanowires are perpendicular to each other,' says Professor Zhipei Sun, who leads the Photonics group at Aalto University.

'The one-dimensional and crossbar structures are the core of our calculations because they enable the input light to choose which nanowire it interacts with--either the indium phosphide or the aluminum gallium arsenide,' adds Dr. He Yang.

Depending on the input, in this case the linearly-polarized light direction and its wavelength, the nanowires either interact with the input light or not. This is similar in practice to how the antennas used in old radio receivers work; they only receive signals when pointing in the optimal direction, typically upwards. Since the response of the different nanomaterials is different, the light output of the fabricated nanowire structure can be switched with different wavelengths and light direction for the successful realization of logic operations.
-end-
The study was published in the latest volume of Science Advances.

Aalto University

Related Nanowires Articles from Brightsurf:

A new, highly sensitive chemical sensor uses protein nanowires
Writing in NanoResearch, a team at UMass Amherst reports that they have developed bioelectronic ammonia gas sensors that are among the most sensitive ever made.

Giving nanowires a DNA-like twist
Argonne National Laboratory played a critical role in the discovery of a DNA-like twisted crystal structure created with a germanium sulfide nanowire, also known as a 'van der Waals material.' Researchers can tailor these nanowires in many different ways -- twist periods from two to twenty micrometers, lengths up to hundreds of micrometers, and radial dimensions from several hundred nanometers to about ten micrometers.

Shell increases versatility of nanowires
Nanowires promise to make LEDs more colorful and solar cells more efficient, in addition to speeding up computers.

Scientists synthesize new nanowires to improve high-speed communication
Scientists from the Institute of Process Engineering, City University of Hong Kong and their collaborators synthesized highly crystalline ternary In0.28Ga0.72Sb nanowires to demonstrate high carrier mobility and fast IR response.

Dose of vitamin C helps gold nanowires grow
Rice University scientists discover a method to turn stubby gold nanorods into gold nanowires of impressive length.

Silver nanowires promise more comfortable smart textiles
In a paper to be published in the forthcoming issue in NANO, researchers from the Nanjing University of Posts and Telecommunications have developed a simple, scalable and low-cost capillary-driven self-assembly method to prepare flexible and stretchable conductive fibers that have applications in wearable electronics and smart fabrics.

Artificial synapses made from nanowires
Scientists from J├╝lich together with colleagues from Aachen and Turin have produced a memristive element made from nanowires that functions in much the same way as a biological nerve cell.

Nanowires could make lithium ion batteries safer
From cell phones and laptops to electric vehicles, lithium-ion batteries are the power source that fuels everyday life.

Scientists have a new way to gauge the growth of nanowires
In a new study, researchers from the US Department of Energy's Argonne and Brookhaven National Laboratories observed the formation of two kinds of defects in individual nanowires, which are smaller in diameter than a human hair.

Cleaning nanowires to get out more light
A simple chemical surface treatment improves the performance of nanowire ultraviolet light-emitting diodes.

Read More: Nanowires News and Nanowires Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.