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.
© 2000 Optical Society of America
Colin J. R. Sheppard, "Validity of the Debye approximation," Opt. Lett. 25, 1660-1662 (2000)