ReFOCUS: Reusing Light for Efficient Fourier Optics-Based Photonic Neural Network Accelerator
Shurui Li, Hangbo Yang, Chee Wei Wong, Volker J. Sorger, Puneet Gupta · 2023
In recent years, there has been a significant focus on achieving low-latency and high-throughput convolutional neural network (CNN) inference. Integrated photonics offers the potential to substantially expedite neural networks due to its inherent low-latency properties. Recently, on-chip Fourier optics-based neural network accelerators have been demonstrated and achieved superior energy efficiency for CNN acceleration. By incorporating Fourier optics, computationally intensive convolution operations can be performed instantaneously through on-chip lenses at a significantly lower cost compared to other on-chip photonic neural network accelerators. This is thanks to the complexity reduction offered by the convolution theorem and the passive Fourier transforms computed by on-chip lenses. However, conversion overhead between optical and digital domains and memory access energy still hinder overall efficiency.