Fiber-Integrated All-Optical Signal Processing Device for Storage and Computing

All-optical signal processing is crucial for high-speed optical fiber communication networks. However, current methods utilizing nonlinear media have limitations such as complex preparation, weak nonlinear effects, and requiring additional energy during operation. To overcome these issues, we demonstrate a fiber-integrated all-optical signal processing device based on Ge₂Sb₂Te₅ (GST). This device can perform a storage function and matrix-vector multiplication (MVM) function. Our device is composed of a single-mode fiber and a step-index multimode fiber with a GST layer deposited on the end face of the multimode fiber. By constructing a special Bessel-like light field, we can achieve the 19-level of storage with low switching energy (90 nJ), large contrast ratio (47%), and fast switching time of a single pulse (200 ns). We also demonstrate MVM operation by connecting two memory units in parallel. These features make our all-optical signal processing unit ideal for data storage/processing applications such as photonic neural networks and neuromorphic computing architectures.