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Staircase lens: a binary and diffractive field curvature corrector.

The optical characteristics of a family of diffractive lenses, called staircase lenses, are discussed. These lenses contribute no optical power and the fourth-order wave aberrations Petzval field curvature, distortion, and chromatic aberrations when collimated illumination is used. A diamond-turned staircase lens comprising 150 steps was manufactured. The test results verify the generation of field curvature and longitudinal chromatic aberration.