Aberration-Invariant Imaging - Spherical Aberration

Images of a bar target taken with a traditonal system under no aberration (left), with a traditional sysem with spherical aberration (middle), and with a aberration-invariant system with spherical aberration (right).

These simulated images represent imaging with a standard imaging system and with an aberration-invariant system under unknown spherical aberration. The left image is a clear image of a bar target under no aberrations. The middle image is the simulated result of a standard system with spherical aberration where W40=2 lambda, or two wavelengths of phase error at the aperture edge. The right image represents imaging with an aberration-invariant system. The amount of spherical aberration for the third image is identical to that of the second.

Imaging with the standard system with this degree of spherical aberration results in a loss of contrast and a spatial resolution decrease of about a factor of two. Imaging with an aberration-invariant system under the same degree of spherical aberration results in no contrast loss and is nearly diffraction-limited.