  Spatial resolution is one of the most important specifications of an imaging
system. Recent results in quantum parameter estimation theory reveal that an
arbitrarily small distance between two incoherent point sources can always be
efficiently determined through the use of a spatial mode sorter. However,
extending this procedure to a general object consisting of many incoherent
point sources remains challenging, due to the intrinsic complexity of
multi-parameter estimation problems. Here, we generalize the Richardson-Lucy
(RL) deconvolution algorithm to address this challenge. We simulate its
application to an incoherent confocal microscope, with a Zernike spatial mode
sorter replacing the pinhole used in a conventional confocal microscope. We
test different spatially incoherent objects of arbitrary geometry, and we find
that the resolution enhancement of sorter-based microscopy is on average over
30% higher than that of a conventional confocal microscope using the standard
RL deconvolution algorithm. Our method could potentially be used in diverse
applications such as fluorescence microscopy and astronomical imaging.
