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Optical Engineering • Open Access

Imaging freeform optical systems designed with NURBS surfaces
Author(s): Michael P. Chrisp; Brian Primeau; Michael A. Echter

Paper Abstract

The designs of two imaging freeform systems using nonuniform rational basis-spline (NURBS) optical surfaces are described. The first system, a 10  deg×9  degf/2 three-mirror anastigmat has four times higher spatial resolution over the image plane compared with the equivalent conventional rotational aspheric design, and 2.5 times higher resolution compared with a 10th-order XY polynomial freeform design. The mirrors for the NURBS freeform design have more than twice the asphericity than the conventional rotational and XY polynomial designs. In the second system, a Ritchey–Chretien telescope followed by a two-mirror NURBS freeform corrector is compared to a four-mirror Korsch telescope, for imaging to a visible-infrared imaging spectrometer. The freeform corrector design had 70% smaller spot sizes over the field and eliminated the large tertiary required in Korsch type design. Both of these NURBS freeform designs are possible due to a custom optical design code for fast accurate NURBS optimization, which now has parallel raytracing for thousands of NURBS grid points.

Paper Details

Date Published: 1 August 2016
PDF: 7 pages
Opt. Eng. 55(7) 071208 doi: 10.1117/1.OE.55.7.071208
Published in: Optical Engineering Volume 55, Issue 7
Show Author Affiliations
Michael P. Chrisp, MIT Lincoln Lab. (United States)
Brian Primeau, MIT Lincoln Lab. (United States)
Michael A. Echter, MIT Lincoln Lab. (United States)
Univ. of Rochester (United States)

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