Engineers at the University of Pennsylvania, Philadelphia, developed a new chip that uses light waves rather than electricity to perform the complex math essential to training AI. The chip has the potential to radically accelerate the processing speed of computers while also reducing their energy consumption.<\/p>\n
The silicon-photonic (SiPh) chip\u2019s design is the first to bring together Benjamin Franklin Medal Laureate and H. Nedwill Ramsey Professor Nader Engheta\u2019s pioneering research in manipulating materials at the nanoscale to perform mathematical computations using light \u2014 the fastest possible means of communication \u2014 with the SiPh platform, which uses silicon, the cheap, abundant element used to mass-produce computer chips.<\/p>\n
The interaction of light waves with matter represents one possible avenue for developing computers that supersede the limitations of today\u2019s chips, which are essentially based on the same principles as chips from the earliest days of the computing revolution in the 1960s.<\/p>\n
In a paper in Nature Photonics<\/em>, Engheta\u2019s group, together with that of Firooz Aflatouni, Associate Professor in Electrical and Systems Engineering, describes the development of the new chip. \u201cWe decided to join forces,\u201d said Engheta, leveraging the fact that Aflatouni\u2019s research group has pioneered nanoscale silicon devices.<\/p>\n Their goal was to develop a platform for performing what is known as vector-matrix multiplication, a core mathematical operation in the development and function of neural networks, the computer architecture that powers today\u2019s AI tools.<\/p>\n Instead of using a silicon wafer of uniform height, explained Engheta, \u201cyou make the silicon thinner, say 150 nanometers,\u201d but only in specific regions. Those variations in height \u2014 without the addition of any other materials \u2014 provide a means of controlling the propagation of light through the chip, since the variations in height can be distributed to cause light to scatter in specific patterns, allowing the chip to perform mathematical calculations at the speed of light.<\/p>\n Due to the constraints imposed by the commercial foundry that produced the chips, Aflatouni said, this design is already ready for commercial applications, and could potentially be adapted for use in graphics processing units (GPUs), the demand for which has skyrocketed with the widespread interest in developing new AI systems. \u201cThey can adopt the Silicon Photonics platform as an add-on,\u201d said Aflatouni, \u201cand then you could speed up training and classification.\u201d<\/p>\n In addition to faster speed and less energy consumption, Engheta and Aflatouni\u2019s chip has privacy advantages: because many computations can happen simultaneously, there will be no need to store sensitive information in a computer\u2019s working memory, rendering a future computer powered by such technology virtually unhackable. \u201cNo one can hack into a non-existing memory to access your information,\u201d said Aflatouni.<\/p>\n <\/p>\n