Rapid reconstruction algorithm for multifocal structured illumination microscopy

Multifocal structured illumination microscopy (MSIM) could surpass the diffraction limit by illuminating the sample with multiple-spot grid patterns. Developed as a parallel version of image scanning microscopy (ISM) to enhance data acquisition speed, MSIM can also be viewed as a variation of structured illumination microscopy (SIM) in which the conventional sinusoidal illumination is substituted with a lattice array of spots. This method outperforms regular SIM when imaging samples that are thick or highly scattered. In this study, we present a rapid reconstruction algorithm for MSIM in the spatial domain and demonstrate that the radius of its equivalent optical transfer function (OTF) support is twice that of a general wide-field microscopy in the epi-illumination geometry. Numerical simulations and experimental results have validated the effectiveness of the proposed algorithm.