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DOE OSTI · 1769028

Ronchi shearing interferometry for wavefronts with circular symmetry

Nagler, Bob·Galtier, Eric C.·Brown, Shaughnessy B.·Heimann, Philip·Dyer, Gilliss·Lee, Hae Ja
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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. Furthermore, 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.

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73 NUCLEAR PHYSICS AND RADIATION PHYSICSgrating interferometrywavefront sensingx-ray FEL

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Nagler, Bob, Galtier, Eric C., Brown, Shaughnessy B., Heimann, Philip, Dyer, Gilliss, Lee, Hae Ja. 2020-09-14. Ronchi shearing interferometry for wavefronts with circular symmetry. https://doi.org/10.1107/s1600577520010735

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