NIR-II Temporal Compressive Wide-Field Microscope (TCWM) Achieving Fluorescent Dynamic Imaging Beyond Camera Frame Rate

Temporal compressive imaging enables the reconstruction of multi-frame dynamic scenes from a single exposure by multiplexing spatially encoded temporal slices. This approach mitigates integration time loss and facilitates high-speed imaging via low-frame-rate cameras. Herein, a second near-infrared (NIR-II) temporal compressive wide-field microscope (TCWM) is established, utilizing the EfficientSCI algorithm for frame reconstruction. Simulations initially verify the transferability of EfficientSCI to biological microscopic imaging. Furthermore, mask acquisition with a spectrally matched NIR backlight proves effective for the high-fidelity reconstruction of fluorescent targets. Utilizing a conventional NIR camera of 25 frames per second (FPS), NIR-II TCWM achieves a maximum in vitro reconstruction rate of 333.3 FPS, surpassing the native frame rate by over 13-fold. Additionally, its robust anti-scattering capability for dynamic imaging at significant depths is substantiated using Intralipid. Finally, NIR-II TCWM is applied to in vivo cerebrovascular imaging at depths up to 300 µm. With a 100 FPS reconstruction frame rate, NIR-II TCWM successfully demonstrates simultaneous, high-speed tracking of multiple fluorescent particles across multiple vessels, highlighting the potential for comprehensive deep-tissue hemodynamic research in living organisms.