Biconic Zernike Surface



The Biconic Zernike Surface is either rectangular or elliptical in shape, or may have a shape defined by a user defined aperture. The surface is described by the following sag equation:

Where

and

Rx and Ry are the radius of curvature values in the x and y directions, kx and ky are the conic constants in the x and y directions, the α terms are the x aspheric coefficients, the β terms are the y aspheric coefficients, N is the number of Zernike coefficients in the series, Ai is the coefficient on the ith Zernike Standard polynomial, r is the radial coordinate in lens units, ρ is the normalized radial coordinate, and is the angular coordinate. The Zernike Standard polynomials are defined in the table given in Zernike Standard Coefficients.

This surface also supports optional X and Y decenters on the Biconic and Zernike terms separately. The biconic decenters are applied to the biconic sag and individual x and y aspheric coefficients, while the Zernike decenters are applied only to the Zernike terms.

The following parameters are used to define the Biconic Zernike Surface:

Parameter # Description Face Name Face #
1-2 The X and Y Half-Width in lens units. If either value is less than zero, the aperture shape will be elliptical, otherwise, the aperture is rectangular, unless a user-defined aperture is applied to the surface. All Faces 0
3-4 The Rx and Ry radii of curvature. Use zero for flat. All Faces 0
5-6 The Kx and Ky conic constants. All Faces 0
7-8 The biconic X and Y direction decenters. All Faces 0
9-10 The Zernike X and Y direction decenters. All Faces 0
11 The number of Standard Zernike terms. All Faces 0
12 The normalization radius for the Zernike terms. All Faces 0
13 Unused. NA NA
14-29 The x direction aspheric α coefficients. All Faces 0
30-45 The y direction aspheric β coefficients. All Faces 0
46-245 The Zernike Standard coefficients. All Faces 0

Face Numbers: All faces Face 0.

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