Annularly apodized beams have been suggested for use in optical storag
e because of their potential to go beyond the conventional spot size a
nd depth-of-focus limits. One concern for such applications is the eff
ects of small aberrations on beams in which the energy is concentrated
in a small annular ring. We present calculations and experimental res
ults that show that annular apodization of a Gaussian beam reduces the
sensitivity to defocus as well as balanced spherical and coma aberrat
ions. The sensitivity to astigmatism is increased by a small amount.