May 3, 2024

1000 Times Faster Processing: Innovative Detector for Large-Scale Optical Neural Networks

Researchers have utilized an SNPD to improve the speed and effectiveness of optical neural networks, showcasing a potential 1000-fold increase in processing speeds compared to traditional cam sensing units. This improvement declares a new period for AI-driven vision systems.
Faster, energy-efficient diffractive ONN might be utilized for image and video processing.
For the very first time, scientists have harnessed the power of a surface area regular nonlinear photodetector (SNPD) to improve the speed and energy efficiency of a diffractive optical neural network (ONN). This innovative device leads the way for the advancement of large-scale ONNs, which can perform high-speed processing at the speed of light in an exceptionally energy-efficient way.
Farshid Ashtiani from Nokia Bell Labs will provide this research at Frontiers in Optics + Laser Science (FiO LS), which will be held October 9-12, 2023, at the Greater Tacoma Convention Center in Tacoma (Greater Seattle Area), Washington.

” However, because the images are originally in the optical domain (i.e., light), it can be quicker and more energy effective to process them optically utilizing ONN. Amongst various innovations, ONNs based on spatial light modulators allow the optical processing of high-resolution images and videos. In the brand-new work, the scientists proposed the use of an SNPD, which they had actually formerly shown as a high-speed electro-optic modulator, in high-resolution diffractive ONNs. Evaluating revealed that the SNPD had a 3-dB bandwidth of 61 kHz corresponding to less than 6 split seconds– about 1000 times faster than the typical response time of cam sensors traditionally used in such ONNs. To gauge the sensors effectiveness within an ONN, the researchers input images into the convolution layer– the primary structure block of the neural network.

“Neural networks, influenced by how the human brain discovers and performs various jobs, are at the heart of the development in AI. One of the widespread applications of neural networks is recognizing things and patterns, which gives vision to machines.
Variety of detectors. Credit: Farshid Ashtiani, Nokia Bell Labs
Conventional Processing vs. Optical Neural Networks
” Conventionally, images are taken by video cameras, converted to electrical signals, and processed utilizing electronic processors such as CPUs or GPUs for things recognition,” stated Mohamad Hossein Idjadi, Nokia Bell Labs.
” However, since the images are initially in the optical domain (i.e., light), it can be quicker and more energy efficient to process them optically utilizing ONN. Amongst various technologies, ONNs based upon spatial light modulators allow the optical processing of high-resolution images and videos. This processing requires nonlinear modules and video camera sensing units are traditionally utilized to introduce this needed nonlinearity, which takes numerous milliseconds.
” Our novel detector device makes this nonlinear processing 1000 times much faster and more energy efficient than such cameras. This is important for the next generation of device vision systems as all of us require even much faster smart gadgets that do not consume a great deal of energy.”
Benefits of Free-space Diffractive ONNs
Free-space diffractive ONNs utilize spatial light modulators and are particularly promising for creating the massive networks of neurons essential for image and video processing. Nevertheless, the speed and energy efficiency of this type of ONN is usually restricted by the image sensor used to implement the nonlinear activation function that executes several layers of neurons to develop a deep neural network.
Single detector. Credit: Farshid Ashtiani, Nokia Bell Labs
In the new work, the scientists proposed the use of an SNPD, which they had previously shown as a high-speed electro-optic modulator, in high-resolution diffractive ONNs. Evaluating showed that the SNPD had a 3-dB bandwidth of 61 kHz representing less than 6 split seconds– about 1000 times faster than the common reaction time of camera sensing units traditionally used in such ONNs. The sensor also takes in only about 10 nW/pixel, which is three orders of magnitude more effective than a normal electronic camera.
Evaluating and Implications
To assess the sensing units efficacy within an ONN, the scientists input images into the convolution layer– the main building block of the neural network. The convolution layer had 32 parallel 3 × 3 kernels with a stride of one and utilized the actually measured SNPD reaction as its activation function rather of the basic corrected linear activation function. With this simulation setup, the network attained a test category precision of about 97%, which is the same efficiency as using a perfect remedied linear activation function in the exact same network.
The research study demonstrates the potential of utilizing a SNPD in free-space diffractive ONNs. The reality that the detector is three orders of magnitude much faster and more effective than a cam makes it a promising candidate for use in large-scale free-space ONN setups.
” We need to make a great deal of our detector devices, potentially millions of them, to build a full vision system, and to complete with the high resolution provided by traditional video cameras,” added Stefano Grillanda, Nokia Bell Labs. “The great news is that this is technologically possible. Another avenue to look into is to further decrease the footprint, energy intake, and reaction time of the detector to make it an even much better solution for future AI vision systems.”
Satisfying: Frontiers in Optics + Laser Science