ALLPCB
Summary
A research team led by Professors Zhiqin Chu, Can Li, and Yi Huang from the Department of Electrical and Electronic Engineering at the University of Hong Kong, in collaboration with scientists from China and Germany, has reported advances in increasing the speed and resolution of widefield quantum sensing.
The team mimicked the human visual system to design a neuromorphic vision sensor that encodes fluorescence intensity changes as pulses during optically detected magnetic resonance (ODMR) measurements, significantly compressing data and reducing latency.
The new quantum sensing system is more efficient than conventional methods and has potential applications in monitoring dynamic processes in biological systems and other fields. The study was published in Advanced Science under the title "Widefield Diamond Quantum Sensing with Neuromorphic Vision Sensors".
Background and Motivation
Researchers worldwide have sought to improve quantum sensing measurement accuracy and spatiotemporal resolution. Current image sensors typically transmit sensor data as image frames to a post-processing unit at rates below 100 frames per second, which significantly limits temporal resolution. Processing the large volumes of frame-based data has been a major challenge in developing new sensing systems; this research aims to address that bottleneck.
Approach
Conventional sensors record light intensity, whereas neuromorphic vision sensors convert intensity changes into pulses analogous to biological visual systems, substantially improving temporal resolution to the microsecond scale and dynamic range to >120 dB. This approach enables capture of finer or faster signal changes, broadening the measurable range of light intensity variations for rapidly changing dynamics. The method also suppresses redundant static background signals, which is especially effective in scenes with infrequent image changes such as target tracking and autonomous vehicles.
The team validated the approach using an off-the-shelf event camera to measure ODMR resonance frequencies. Event cameras output data only when significant changes occur in the scene, unlike conventional cameras that continuously capture image frames at fixed time intervals.
In one experiment, the researchers coated diamond surfaces with gold nanoparticles and used laser-induced temperature changes on the diamond surface for detection. "Using the new technique, we successfully monitored temperature changes on the diamond surface with gold nanoparticles. This would be difficult with existing methods," Du said.
Results
Compared with state-of-the-art frame-based techniques, the neuromorphic sensing approach achieved comparable accuracy while improving temporal resolution by a factor of 13. The system reaches approximately microsecond-scale timing and a dynamic range exceeding 120 dB, enabling detection of rapid and small signal changes with reduced data volume and latency.
Implications and Future Work
Du Zhiyuan was inspired by his supervisor's work in quantum sensing and, driven by his interest in combining sensing and computation for intelligent data processing and analysis, focused his research and that of other team members on quantum sensing.
"Our research provides a new approach to developing high-precision, low-latency widefield quantum sensing. Integration of the technique with emerging memory-based synaptic devices could enable more intelligent quantum sensors in the future," he added.
Concept, Design, and Implementation
"Our new method will transform widefield quantum sensors, substantially improving performance at acceptable cost," Professor Zhiqin Chu said.
"It also brings practical closer the implementation of near-sensor processing using novel memory-based electronic synaptic devices," Professor Can Li said.
"The technology's industrial applications require further exploration, such as studying dynamic current changes in materials and identifying defects in microchips," Professor Yi Huang said.
