MIT spin-off raises funds for optical processor

LightmatterLightmatter Inc. (Boston, Mass.), a company developing a photonic processor for neural network applications, has received $11 million in Series A funds.

Although analog computing simple digital operations using operations were demonstrated many years ago the complexity of digital architectures, the incomplete set of photonic equivalents to electronic circuits and the need to move out of and back into the optical domain has held back the use of photonic computing.

Lightmatter has homed in on the artificial intelligence domain where digital operations are more uniform than in general purpose computing and produced a silicon chip that uses light signals, rather than electrical signals, for matrix multiplication.

The system uses heated silicon channels between Mach-Zehnder interferometers to slow down, to varying degrees, optical signals that represent weights. As the signals pass through a cascade of interferometers the input weights are matrix multiplied to produce the required outputs.

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