Table 1.
n | Zn(r,θ) | RMS | Name | ||
---|---|---|---|---|---|
2nd order | 3 | r2 sin(2θ) |
|
astigmatism | |
4 | 2r2 – 1 |
|
defocus | ||
5 | r2 cos(2θ) |
|
astigmatism | ||
| |||||
3rd order | 6 | r3 sin(3θ) |
|
trefoil | |
7 | (3r3 – 2r) sin(θ) |
|
coma | ||
8 | (3r3 – 2r) cos(θ) |
|
coma | ||
9 | r3 sin(3θ) |
|
trefoil | ||
| |||||
4th order | 10 | r4 sin(4θ) |
|
quadrafoil | |
11 | (4r4 – 3r2) sin(2θ) |
|
secondary astigmatism | ||
12 | 6r4 – 6r2 + 1 |
|
spherical | ||
13 | (4r4 – 3r2) cos(2θ) |
|
secondary astigmatism | ||
14 | r4 cos(4θ) |
|
quatrefoil |