Effects of inhomogeneous fields in superresolving structured-illumination microscopy

The increased resolution attained by structured illumination is based on the degree to which high spatial frequencies can be down converted into the passband of the imaging system. To effectively do this, a high contrast high-frequency illumination pattern is required. We show how the use of high numerical aperture (1.42 NA and 1.65 NA) microscope objectives in structured-illumination microscopy can provide relatively high-frequency illumination patterns. However, a consequence of this is that the resulting illumination pattern can become evanescently decaying and thus becomes inhomogeneous within a microscopically extended sample medium. We demonstrate how these inhomogeneous fields impact the superresolved imaging of the microscope and how these adverse effects can be avoided.