  Ultrafast 3D imaging is indispensable for visualizing complex and dynamic
biological processes. Conventional scanning-based techniques necessitate an
inherent trade-off between acquisition speed and space-bandwidth product (SBP).
Emerging single-shot 3D wide-field techniques offer a promising alternative but
are bottlenecked by the synchronous readout constraints of conventional CMOS
systems, thus restricting data throughput to maintain high SBP at limited frame
rates. To address this, we introduce EventLFM, a straightforward and
cost-effective system that overcomes these challenges by integrating an event
camera with Fourier light field microscopy (LFM), a state-of-the-art
single-shot 3D wide-field imaging technique. The event camera operates on a
novel asynchronous readout architecture, thereby bypassing the frame rate
limitations inherent to conventional CMOS systems. We further develop a simple
and robust event-driven LFM reconstruction algorithm that can reliably
reconstruct 3D dynamics from the unique spatiotemporal measurements captured by
EventLFM. Experimental results demonstrate that EventLFM can robustly
reconstruct fast-moving and rapidly blinking 3D fluorescent samples at kHz
frame rates. Furthermore, we highlight EventLFM's capability for imaging of
blinking neuronal signals in scattering mouse brain tissues and 3D tracking of
GFP-labeled neurons in freely moving C. elegans. We believe that the combined
ultrafast speed and large 3D SBP offered by EventLFM may open up new
possibilities across many biomedical applications.
