Quantitative sectioning and noise analysis for structured illumination microscopy: erratum.

We correct an error in the original manuscript, where an unrecognized assumption was made about the relationship between the out-of-focus light and the in-focus light. We summarize the condition under which the assumption may still hold, and mention alternative methods researchers can use to obtain accurate quantitative sectioning.

Correction of astigmatism and coma using analytic theory of aberrations in imaging spectrometer based on concentric off-axis dual reflector system.

A specific imaging spectrometer based on a concentric off-axis dual reflector system is proposed, free of astigmatism and coma. The described imaging spectrometer consists of four spherical mirrors and a plane grating. The analytic theory of aberrations and the optical path-length concept are used to derive the astigmatism elimination and coma removal.