Researchers at the National Institute of Standards and Technology (NIST) have made a silicon chip that distributes optical signals precisely across a miniature brain-like grid, showcasing a potential new design for neural networks.
The human brain has billions of neurons (nerve cells), each with thousands of connections to other neurons. Many computing research projects aim to emulate the brain by creating circuits of artificial neural networks. But conventional electronics, including the electrical wiring of semiconductor circuits, often impedes the extremely complex routing required for useful neural networks.
The NIST team proposes to use light instead of electricity as a signaling medium. Neural networks already have demonstrated remarkable power in solving complex problems, including rapid pattern recognition and data analysis. The use of light would eliminate interference due to electrical charge, and the signals would travel faster and farther.
“Light’s advantages could improve the performance of neural nets for scientific data analysis such as searches for Earth-like planets and quantum information science, and accelerate the development of highly intuitive control systems for autonomous vehicles,” NIST physicist Jeff Chiles said.
A conventional computer processes information through algorithms, or human-coded rules. By contrast, a neural network relies on a network of connections among processing elements, or neurons, which can be trained to recognize certain patterns of stimuli. A neural or neuromorphic computer would consist of a large, complex system of neural networks.
Described in a new paper, the NIST chip overcomes a major challenge to the use of light signals by vertically stacking two layers of photonic waveguides—structures that confine light into narrow lines for routing optical signals, much as wires route electrical signals. This three-dimensional (3D) design enables complex routing schemes, which are necessary to mimic neural systems. Furthermore, this design can easily be extended to incorporate additional waveguiding layers when needed for more complex networks.
The stacked waveguides form a three-dimensional grid with 10 inputs or “upstream” neurons each connecting to 10 outputs or “downstream” neurons, for a total of 100 receivers. Fabricated on a silicon wafer, the waveguides are made of silicon nitride and are each 800 nanometers (nm) wide and 400 nm thick. Researchers created software to automatically generate signal routing, with adjustable levels of connectivity between the neurons.
Laser light was directed into the chip through an optical fiber. The goal was to route each input to every output group, following a selected distribution pattern for light intensity or power. Power levels represent the pattern and degree of connectivity in the circuit. The authors demonstrated two schemes for controlling output intensity: uniform (each output receives the same power) and a “bell curve” distribution (in which middle neurons receive the most power, while peripheral neurons receive less).
To evaluate the results, researchers made images of the output signals. All signals were focused through a microscope lens onto a semiconductor sensor and processed into image frames. This method allows many devices to be analyzed at the same time with high precision. The output was highly uniform, with low error rates, confirming precise power distribution.
“We’ve really done two things here,” Chiles said. “We’ve begun to use the third dimension to enable more optical connectivity, and we’ve developed a new measurement technique to rapidly characterize many devices in a photonic system. Both advances are crucial as we begin to scale up to massive optoelectronic neural systems.”
Learn more: NIST Chip Lights Up Optical Neural Network Demo
The Latest on: Optical neural network
[google_news title=”” keyword=”optical neural network” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Optical neural network
- Dutch discovery brings energy-efficient computers a step closeron March 26, 2023 at 10:30 pm
An international group of researchers at the University of Twente have developed a molecular switch that can increase the energy-efficiency of electronics.
- Study shows artificial Intelligence can predict genetics of cancerous brain tumorson March 26, 2023 at 10:06 am
Researchers have made an AI-based diagnostic screening system called DeepGlioma that uses rapid imaging to analyze tumor specimens taken during an operation and ...
- A new approach to optical sensing, an increasingly in-demand technologyon March 24, 2023 at 6:31 am
In the past decade, optical sensing tasks have become more demanding. As a result, it has become critical to build miniaturized, inexpensive sensors that can be integrated on-chip to enable mobile ...
- Artificial intelligence predicts genetics of cancerous brain tumors in under 90 secondson March 22, 2023 at 5:00 pm
Using artificial intelligence, researchers have discovered how to screen for genetic mutations in cancerous brain tumors in under 90 seconds -- and possibly streamline the diagnosis and treatment of ...
- Researchers Build ‘Living Computer’ Using Mouse Brain Cellson March 22, 2023 at 8:34 am
Andrew Dou, a graduate student at UIUC’s Holonyak Micro & Nanotechnology Lab, led a team of researchers through reprogramming mouse stem cells to obtain a collection of neurons. The team then grew ...
- Samsung responds to fake Moon controversyon March 15, 2023 at 8:16 am
These criticisms aren’t new ( Input published a lengthy piece about Samsung’s moon photography in 2021) but the simplicity of the test brought the issue greater attention: Reddit user ibreakphotos ...
- News tagged with neural networkon March 12, 2023 at 5:00 pm
In the past decade, optical sensing tasks have become more ... They trained a convolutional neural network (CNN) with microscopy images of ...
- Optical techniques for the recording and manipulation of neural activity in-vivoon June 8, 2022 at 4:39 pm
These techniques afford either bulk or single-cell calcium imaging of neural activity with high temporal and spatial resolution in behaving animals. Since the first exploration of optical ...
- Professors by Expertiseon August 14, 2020 at 2:41 pm
Dr. Sébastien Le Beux Design methods for emerging (nano)technologies and embedded systems; Network-on-Chip, System on Chip, Optical neural networks, Silicon photonic interconnect; Reconfigurable ...
via Bing News