Spatial-Dispersion Cancellation in Quantum Interferometry

We investigate cancellation of spatial aberrations induced by an object placed in a quantum coincidence interferometer with type-II parametric down conversion as a light source. We analyze in detail the physical mechanism by which the cancellation occurs, and show that the aberration cancels only when the object resides in one particular plane within the apparatus. In addition, we show that for a special case of the apparatus it is possible to produce simultaneous cancellation of both even-order and odd-order aberrations in this plane.