posted on 2023-11-09, 17:40authored byJiapeng Sun, Hanyang Li, Yifan Qin, Siying Cheng, Jinhua Mou, Jiaxing Gao, Yu Zhang, Zhihai Liu
Developing
an optical fiber storage platform that integrates storage
and computation poses a challenge. This article presents a bipolar
memory that incorporates phase change materials by combining two tapered
fibers with a microsphere. The state of Ge2Sb2Te5 is altered by modulating an external laser, resulting
in repeatable or randomly accessible five-level data storage. Multistage
writing is achieved using a 532 nm pump laser and laser energy levels
ranging from 0.423 to 1.206 mJ, while a 793 nm continuous wave laser
with an average power of 4 to 11 mW completes the multistage reset.
The bipolar memory demonstrates nonvolatility, high signal-to-noise
ratio, excellent repeatability, 75 ns write response time, 180 ns
reset response time, and 18 dB contrast. Furthermore, we develop a
continuous programming platform using quaternary ASCII coding as an
alternative to English letters. The bipolar memory can implement the
synaptic weight update mechanism within the neural network system’s
synapses, thereby showcasing excellent data storage, programming,
and neural network computing potential.