title: Validity of the Debye approximation.
abstract: The validity of the Debye approximation is reexamined. It is shown that for paraxial systems with strong aberrations the Debye approximation may not be valid, even for systems with a large Fresnel number. The particular case of spherical aberration is considered. Extension to high-aperture systems is discussed.
authors: C J
authors: CJ
authors: Sheppard