Lensless imaging: a workshop on "new approaches to the phase problem for non-periodic objects.".

Over the past two decades, theoretical tools and algorithms have been developed which, under not very restrictive conditions, allow the reconstruction of images from diffraction patterns of non-periodic objects. These methods promise lensless imaging for any radiation, free of aberrations, with wavelength-limited resolution. Recent experimental successes prompted an interdisciplinary international workshop on this topic at the Lawrence Berkeley National Laboratory, Berkeley, CA, USA, on May 17-19 2001, supported by the DOE, LBL and the Advanced Light Source. Our aim was to review the field, and to stimulate communication between the Signal Recovery, Coherent Optics, X-ray, Electron Microscopy and Applied Mathematics communities. The results are summarized in this paper and on the web. A second workshop is planned for 2003.