Synthetic Incoherence via Scanned Gaussian Beams.
Tomography, in most formulations, requires an incoherent signal. For a conventional transmission electron microscope, the coherence of the beam often results in diffraction effects that limit the ability to perform a 3D reconstruction from a tilt series with conventional tomographic reconstruction algorithms. In this paper, an analytic solution is given to a scanned Gaussian beam, which reduces the beam coherence to be effectively incoherent for medium-size (of order 100 voxels thick) tomographic applications. The scanned Gaussian beam leads to more incoherence than hollow-cone illumination.
National Institute of Standards and Technology, Gaithersburg, MD 20899-8410.
Zachary H
ZH
Levine
Gaussian beams; electron microscopy; incoherence; synthetic incoherence