3D quantitative tomographic microscopy of low-contrast structures

The Phase Focus Virtual Lens® (otherwise known as ptychography) is a new microscopy
method that eliminates the need for hardware focusing components, thereby removing the
straitjacket imposed by the costs, limitations and imperfections of conventional lenses.
Instead of lenses, the Virtual Lens image reconstruction process is performed by a
sophisticated computer programme (algorithm.) Because it provides quantitative (numerical)
information, and because it can extract the high information content often present in
transparent specimens, the Virtual Lens has advantages in applications as diverse as live cell
imaging and ophthalmic (contact) lens manufacture.
The existing Virtual Lens algorithm relies on a two-dimensional mathematical approximation
of the specimen. If the specimen’s structure is physically three-dimensional, or if it is thick,
poor image quality can result. The purpose of this work, therefore, is to produce full
tomographic quantitative images of low-contrast specimens of complex structures, using a
new three-dimensional Virtual Lens algorithm.
If successful, it is expected that this new method will be able to generate high quality and
accurate information from such specimens without the use of stains, and from greater depths
within the specimens than can be observed using conventional confocal microscopes.
In addition, the technique is expected to be able to provide a new way to measure accurately,
for manufacturing quality assurance purposes, the full three dimensional shape of lenses that
are used in CD and DVD players, mobile phones, microscopes, telescopes and other products.
It is anticipated that this work will therefore create new and improved products and processes
for the benefit of UK industry and society at large.