Abstract

Soft x-ray holographic microscopy offers the promise of producing images of hydrated biological specimens at a transverse resolution of a few hundred angstroms.¹ Using a soft x-ray undulator National Synchrotron Light Source and a monochromator and spatial filter pinhole, we coherently illuminate our specimen (air-dried rat pancreatic zymogen granules) and recording medium (a photoresist) with 25-A soft x rays.² By using the Gabor holographic geometry, we are able to bypass the technological difficulties of making high-resolution x-ray optical elements. The processed holograms are enlarged with an electron microscope and digitized, and a reconstructed image is obtained numerically using a computer. In this manner, we obtained images of air-dried rat pancreatic zymogen granules which exhibit sub-1000-A resolution and which yield information not available in 100-keV electron or optical images of similarly prepared specimens.

© 1988 Optical Society of America