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Limitations Of Aberration Correction In Spectrometer Imaging

The limitations of aberration correction to spectrometer imaging by holographic and variable line-space gratings are addressed in light of recent theoretical analyses. Aberration reduction is discussed for particular mountings, specifically flat-field spectrographs, Rowland circle spectrographs and constant deviation monochromators. For these mounts, it is argued that aberration reduction via modification of the groove pattern alone cannot completely correct even the lowest-order aberrations over an arbitrary wavelength range.