We present a general proof of the distortion-correction theorem, that is, o
f the possibility of correcting wave distortion by the technique of optical
phase conjugation. The proof is valid for fully vectorial nonparaxial prop
agation in the presence of a tensorial refractive-index perturbation and ba
ckscattering of the incident field. (C) 2001 Optical Society of America OCI
S codes: 190.5040, 260.2110.