title: Equivalence of focusing conditions for holographic and varied line-space grating systems.
abstract: The focal conditions for diffraction grating systems that employ holographic and varied line-space gratings are shown to be formally identical. An example is given in which the recording geometry of a holographic grating is derived that provides the same imaging (to lowest order) as a ruled grating whose grooves, while straight and parallel, vary in spacing across the surface of the grating.
authors.forename: C
authors.initials: C
authors.lastname: Palmer
authors.forename: W R
authors.initials: WR
authors.lastname: McKinney