Structured illumination imaging with quasi-periodic patterns.

Structured illumination microscopy (SIM) is a well-established method for optical sectioning and super-resolution. The core of structured illumination is using a periodic pattern to excite image signals. This work reports a method for estimating minor pattern distortions from the raw image data and correcting these distortions during SIM image processing. The method was tested with both simulated and experimental image data from two-photon Bessel light-sheet SIM. The results proves the method is effective in challenging situations, where strong scattering background exists, signal-to-noise ratio (SNR) is low and the sample structure is sparse. Experimental results demonstrate restoring synaptic structures in deep brain tissue, despite the presence of strong light scattering and tissue-induced SIM pattern distortion.