Femto-joule threshold reconfigurable all-optical nonlinear activators for picosecond pulsed optical neural networks
Ruizhe Liu, Zijia Wang, Chuyu Zhong, Yan Chen, Boshu Sun, Jialing Jian, Hui Ma, Dawei Gao, Jianyi Yang, Lan Li, Kaihui Liu, Xiaoyong Hu, Hongtao Lin · Light Science & Applications · 2026
Abstract Achieving optical computing with thousands of tera-operations per second per watt per square millimeter (TOPs/W/mm 2 ) is the key to surpassing electrical computing. This realization requires a breakthrough in the design of a new optical computing architecture and nonlinear activation functions. By leveraging the Kerr effect of silicon and the saturable absorption of graphene, we designed an all-optical nonlinear activator based on a graphene-silicon integrated photonic crystal cavity. The ultralow-threshold, high-speed, compact, and reconfigurable all-optical nonlinear activator could achieve a saturable absorption energy threshold of 4 fJ and a response time of 1.05 ps, a reconfigurable nonlinear activation threshold of 30 fJ and a response time of 4 ps, and an ultrasmall size of 15 μm × 10 μm. This device provides foundation blocks for the picosecond pulsed optical neural network chip to achieve 10 6 TOPs/W/mm 2 level optical computing.