Coherent diffraction, partial coherence and phase diversity
by
Prof.Keith A Nugent(ARC Centre of Excellence for Coherent X-ray Science School of Physics, The University of Melbourne)
→
Europe/Rome
Aula Conversi (Dipartimento di Fisica - Ed. G. Marconi)
Aula Conversi
Dipartimento di Fisica - Ed. G. Marconi
Description
Coherent diffractive imaging (CDI) is a rapidly emerging area
of research that is now beginning to see application to important
problems in biology and materials science. In this talk I will review
the historical development and current state of the field with a
particular emphasis on work using synchrotron sources and free
electron lasers. Modern X-ray lasers are not perfectly coherent and so
I will also discuss the impact of the partial coherence of the light
on the ability to reconstruct a reliable high-resolution image. In
particular, I will discuss the work of my group in which we have
measured the coherence properties and included them into the imaging
process. I will also introduce the concept of phase-diversity in
coherent X-ray imaging and I will present experimental data that I
hope will convince you that coherent techniques are now able to
produce very reliable high-resolution X-ray imaging of biological
samples. An important potential application of CDI is to molecular
imaging with a free electron laser. I will argue that the impact of
the intense X-ray field on the molecule can be treated as a form of
partial coherence and discuss how these ideas might ultimately be used
to account for the effects of damage from the laser pulse and lead to
reliable imaging of single molecules
