The Zernike polynomials are a set of orthogonal polynomials that arise in the expansion of a wavefront function for optical systems with circular pupils. The odd and even Zernike polynomials are given by
|
(1)
|
where the radial function is defined for
and
integers with
by
|
(2)
|
Here,
is the azimuthal angle with
and
is the radial distance with
(Prata and Rusch 1989). The even and odd polynomials
are sometimes also denoted
|
(3)
| |||
|
(4)
|
Zernike polynomials are implemented in the Wolfram Language as ZernikeR[n, m, rho].
Other closed forms for include
|
(5)
|
for
odd and
,
where
is the gamma function and
is a hypergeometric
function. This can also be written in terms of the Jacobi
polynomial
as
|
(6)
|
The first few nonzero radial polynomials are
|
(7)
| |||
|
(8)
| |||
|
(9)
| |||
|
(10)
| |||
|
(11)
| |||
|
(12)
| |||
|
(13)
| |||
|
(14)
| |||
|
(15)
|
(Born and Wolf 1989, p. 465).
The radial functions satisfy the orthogonality relation
|
(16)
|
where
is the Kronecker delta, and are related to the
Bessel function of the first kind
by
|
(17)
|
(Born and Wolf 1989, p. 466). The radial Zernike polynomials have the generating function
|
(18)
|
(correcting the typo of Born and Wolf) and are normalized so that
|
(19)
|
(Born and Wolf 1989, p. 465).
The Zernike polynomials also satisfy the recurrence relations
|
(20)
|
(Prata and Rusch 1989). The coefficients and
in the expansion of an arbitrary radial function
in terms of Zernike polynomials
|
(21)
|
are given by
|
(22)
|
where
|
(23)
|
Let a "primary" aberration be given by
|
(24)
|
with
and where
is the complex conjugate of
, and define
|
(25)
|
giving
|
(26)
|
Then the types of primary aberrations are given in the following table (Born and Wolf 1989, p. 470).
| aberration | |||||
| spherical aberration | 0 | 4 | 0 | ||
| coma | 0 | 3 | 1 | ||
| astigmatism | 0 | 2 | 2 | ||
| field curvature | 1 | 2 | 0 | ||
| distortion | 1 | 1 | 1 |