Table 1.

Summary of the effects of small amplitude aberrations on the zero of the depletion focus.

Azimuthal order $m$	Type	2D STED	3D STED
0	Defocus, sphericals	No effect	Axial shift
1	Coma	Lateral shift	Lateral shift
2	Astigmatism	Zero fills in	Zero fills in
3	Trefoil	Zero fills in	No effect
$\ge 4$	–	No effect	No effect