Line-scan focal modulation microscopy for rapid imaging of thick biological specimens

In recent development of fluorescence microscopy, the out-of-focus fluorescence background that arises when imaging deep inside biological tissues is critical in determining the image quality and penetration depth. Focal Modulation Microscopy [1–3] (FMM) is an emerging single-photon excitation fluorescence microscopy technique that can provide sub-micron spatial resolution for deep imaging of biological tissues mainly by preserving the signal-to-background ratio. Here we report a line-scan FMM that enables line-by-line recording [4] at video frame rates (>30 fps) depending on the size of region of interest.