Photonic integrated spiking neuron chip based on a self-pulsating DFB laser with a saturable absorber

作者：Yuechun Shi, Shuiying Xiang, Xingxing Guo, Yahui Zhang, Hongji Wang, Dianzhuang Zheng, Yuna Zhang, Yanan Han, Yong Zhao, Xiaojun Zhu, Xiangfei Chen, Xun Li, Yue Hao · 发表于：Photonics Research · 年份：2023 · DOI：10.1364/prj.485941 · 被引用次数：42 · 研究领域：Neural Networks and Reservoir Computing、Optical Network Technologies、Photonic and Optical Devices

We proposed and experimentally demonstrated a simple and novel photonic spiking neuron based on a distributed feedback (DFB) laser chip with an intracavity saturable absorber (SA). The DFB laser with an intracavity SA (DFB-SA) contains a gain region and an SA region. The gain region is designed and fabricated by the asymmetric equivalent π -phase shift based on the reconstruction-equivalent-chirp technique. Under properly injected current in the gain region and reversely biased voltage in the SA region, periodic self-pulsation was experimentally observed due to the Q -switching effect. The self-pulsation frequency increases with the increase of the bias current and is within the range of several gigahertz. When the bias current is below the self-pulsation threshold, neuronlike spiking responses appear when external optical stimulus pulses are injected. Experimental results show that the spike threshold, temporal integration, and refractory period can all be observed in the fabricated DFB-SA chip. To numerically verify the experimental findings, a time-dependent coupled-wave equation model was developed, which described the physics processes inside the gain and SA regions. The numerical results agree well with the experimental measurements. We further experimentally demonstrated that the weighted sum output can readily be encoded into the self-pulsation frequency of the DFB-SA neuron. We also benchmarked the handwritten digit classification task with a simple single-layer full...