Abstract

We describe a laboratory experiment that demonstrates diffraction-limited imaging in the presence of aberrations in the imaging system. It is well known that in stellar-speckle interferometry, short-exposure speckle images carry diffraction-limited information in spite of the presence of atmospheric turbulence and the aberration in the telescope. In our experiment a phase plate, which simulates the random phase fluctuation of atmospheric turbulence, is artificially introduced in the pupil plane of the imaging system. This phase plate serves to eliminate the effect of aberrations in the imaging lens. We use triple-correlation methods to recover the object from speckled images produced by random phase fluctuations and aberrations. The bispectrum, calculated from the measured image intensity, is averaged over an ensemble of realizations. From this averaged bispectrum, the object is recovered by using established techniques. As an application, we may use the triple-correlation technique to obtain the diffraction-limited images of the human retina.

© 1990 Optical Society of America