Volume 27, Issue 6 pp. 1461-1469
research papers

Ronchi shearing interferometry for wavefronts with circular symmetry

Bob Nagler

Corresponding Author

Bob Nagler

SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA94025, USA

Bob Nagler, e-mail: [email protected]Search for more papers by this author
Eric C. Galtier

Eric C. Galtier

SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA94025, USA

Search for more papers by this author
Shaughnessy B. Brown

Shaughnessy B. Brown

SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA94025, USA

Stanford University, 450 Serra Mall, Stanford, CA94305, USA

Search for more papers by this author
Philip Heimann

Philip Heimann

SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA94025, USA

Search for more papers by this author
Gilliss Dyer

Gilliss Dyer

SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA94025, USA

Search for more papers by this author
Hae Ja Lee

Hae Ja Lee

SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA94025, USA

Search for more papers by this author
First published: 14 September 2020

Abstract

Ronchi testing of a focused electromagnetic wave has in the last few years been used extensively at X-ray free-electron laser (FEL) facilities to qualitatively evaluate the wavefront of the beam. It is a quick and straightforward test, is easy to interpret on the fly, and can be used to align phase plates that correct the focus of aberrated beams. In general, a single Ronchigram is not sufficient to gain complete quantitative knowledge of the wavefront. However the compound refractive lenses that are commonly used at X-ray FELs exhibit a strong circular symmetry in their aberration, and this can be exploited. Here, a simple algorithm that uses a single recorded Ronchigram to recover the full wavefront of a nano-focused beam, assuming circular symmetry, is presented, and applied to experimental measurements at the Matter in Extreme Conditions instrument at the Linac Coherent Light Source.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.