Background-enhanced NIR-II single-pixel imaging for fluorescent localization and dynamic tracking

Near-infrared-II (NIR-II) fluorescence imaging offers high contrast and reduced scattering but lacks morphological context, posing challenges for precise pathological localization. Conventional fusion using heterogeneous camera arrays suffers from perspective-induced parallax and registration errors. Here, we present a background-enhanced NIR-II single-pixel imaging system for high-fidelity fluorescent localization and dynamic tracking. By employing a shared spatial encoding strategy with parallel silicon and InGaAs detectors, the system eliminates geometric distortions between background and fluorescence images, enabling precise localization without additional alignment algorithms. To address weak signal intensity in dynamic scenes, we further employed a bowl-shaped detector to enhance light collection efficiency, yielding a ~7-fold signal-to-noise ratio improvement. This enabled dynamic fluorescence tracking at 10 fps (sampling rate = 3.05%) with a physical pixel of 128 × 128. This work proposes what we believe to be a novel NIR-II imaging architecture that achieves precise localization and dynamic tracking of fluorescent signals within an anatomical background, offering a new solution for future surgical navigation.