Biomedical subjects

H M L Faulkner

Publications and source records attributed to H M L Faulkner.

2 recordsLinked to original sources

PubMed2004

Error tolerance of an iterative phase retrieval algorithm for moveable illumination microscopy.

This paper examines the behaviour of the new Ptychographical Iterative Engine (PIE) algorithm when part of the initial information it requires is inaccurately known. This could be the parameters describing the illuminating wavefunction, the precise location of the specimen relative to the illuminating wavefunction, or other information that is assumed about the physical system. The tolerance of the algorithm for unavoidable problems such as noise and source incoherence is also investigated, leading to the conclusion that this approach to phase retrieval is very robust. It can not only tolerate errors in the assumed parameters, but can often be used as a method of characterising the parameters more accurately.

Journal Article↗

PubMed2004

Movable aperture lensless transmission microscopy: a novel phase retrieval algorithm.

We propose an iterative phase retrieval method that uses a series of diffraction patterns, measured only in intensity, to solve for both amplitude and phase of the image wave function over a wide field of view and at wavelength-limited resolution. The new technique requires an aperture that is scanned to two or more positions over the object wave function. A simple implementation of the method is modeled and demonstrated, showing how the algorithm uses overlapping data in real space to resolve ambiguities in the solution. The technique opens up the possibility of practical transmission lensless microscopy at subatomic resolution using electrons, x rays, or nuclear particles.

Journal Article↗