FIG. 6.

Image formation in conventional wide-field (A) and structured illumination (B) microscopy. In structured illumination microscopy, high-frequency components in the sample can be imaged as a result of the frequency shift by the structured illumination; however, they overlap with lower-frequency image components. Three overlapped components are extracted and reconstructed in the frequency domain. Inverse Fourier transform allows the reconstruction of a fluorescence image with high spatial-frequency information. The circled X represents convolution. OTF, optical transfer function; PSF, point spread function. (From Yamanaka et al.⁵⁸)