Hardware-aware Lightweight Photonic Spiking Neural Network for Pattern Classification

TL;DR

This paper presents a hardware-aware lightweight photonic spiking neural network architecture tailored for photonic neuromorphic chips, demonstrating high accuracy and energy efficiency in pattern classification tasks.

Contribution

It introduces a novel integrated hardware-software approach with optimized photonic components and a dimension-reduction technique for scalable photonic SNN deployment.

Findings

Achieved 90% accuracy on MNIST with photonic SNN

Energy efficiency of 1.39 TOPS/W for MZI mesh

Demonstrated end-to-end inference on photonic chips

Abstract

There exists a significant scale gap between photonic neural network integrated chips and neural networks, which hinders the deployment and application of photonic neural network. Here, we propose hardware-aware lightweight spiking neural networks (SNNs) architecture tailored to our photonic neuromorphic chips, and conducts hardware-software collaborative computing for solving patter classification tasks. Here, we employed a simplified Mach-Zehnder interferometer (MZI) mesh for performing linear computation, and 16-channel distributed feedback lasers with saturable absorber (DFB-SA) array for performing nonlinear spike activation. Both photonic neuromorphic chips based on the MZI mesh and DFB-SA array were designed, optimized and fabricated. Furthermore, we propose a lightweight spiking neural network (SNN) with discrete cosine transform to reduce input dimension and match the input/output ports number of the photonic neuromorphic chips. We demonstrated an end-to-end inference of an entire layer of the lightweight photonic SNN. The hardware-software collaborative inference accuracy is 90% and 80.5% for MNIST and Fashion-MNIST datasets, respectively. The energy efficiency is 1.39 TOPS/W for the MZI mesh, and is 987.65 GOPS/W for the DFB-SA array. The lightweight architecture and experimental demonstration address the challenge of scale mismatch between the photonic chip and SNN, paving the way for the hardware deployment of photonic SNNs.