Tomographic studies of submicrometer samples in materials science using electron microscopy have been inhibited by diffraction effects. In the present work, we describe a practical method for ameliorating these effects. First, we find an analytic expression for the mutual coherence function for hollow-cone illumination. Then, we use this analytic expression to propose a Gaussian weighting of hollow-cone illumination, which we name tapered solid-cone illumination, and present an analytic expression for its mutual coherence function. Finally, we investigate numerically an n-ring approximation to tapered solid-cone illumination. The results suggest a method for removing diffraction effects and hence enabling tomography.
© 2007 Optical Society of America
Original Manuscript: October 31, 2006
Manuscript Accepted: March 6, 2007
Published: July 11, 2007
Vol. 2, Iss. 9 Virtual Journal for Biomedical Optics
Zachary H. Levine and Robyn M. Dunstan, "Synthetic incoherence for electron microscopy," J. Opt. Soc. Am. A 24, 2402-2406 (2007)