Reconfigurable All-Optical Synapse Based on Photonic Crystal Nanobeam Cavities with Ferroelectric Carrier Injection Valve

Synaptic activity is fundamental to memory and learning in the nervous system. However, most artificial synaptic devices are limited to mimicking static plasticity, and tunable plasticity has not been achieved at the device level. Here, we introduce a dynamic all-optical synapse based on photonic crystal nanobeam cavities with a ferroelectric carrier injection valve. By leveraging the nonlinear and ferroelectric electrostatic doping effects in silicon, integrated with Hf0.5Zr0.5O2 (HZO) film as the ferroelectric layer and indium tin oxide (ITO) as the top electrode, we enhance linearity and reduce power consumption. Increasing the bias voltage further improves linearity while decreasing power consumption. This innovation offers a promising pathway for developing energy-efficient nanophotonic devices in neuromorphic computing.