Abstract

Phase conjugation is in its basic form a double-pass technique; thus the image forms on the object side of the imaging system, which is a severe and often intolerable restriction. A single-pass technique has been described which removes this limitation, but its phase error correction capability is only approximate. We describe a method which allows great improvement in the one-way method. This method involves combining the phase conjugation method with a related method for imaging through inhomogeneities, sometimes called super-resolution by incoherent-to-coherent conversion.¹ The spatial coherence of the illumination is reduced, thus leading to a partially coherent system. Also, the aperture of the imaging system is reduced, thus reducing the magnitude of the inhomogeneity. The reduction of the aperture in combination with the coherence reduction leaves the theoretical resolution unaltered. However, the residual uncompensated phase error is significantly reduced. We have previously described and demonstrated a related technique, which combines superresolution with the double-pass phase conjugation method for imaging through inhomogeneities.² Here we demonstrate that the new configuration, using the single-pass method of phase conjugation, fits better with superresolution; therefore, imaging through inhomogeneous media can be optimized.

© 1988 Optical Society of America