Conception of diffractive wavefront correction for XUV and soft x-ray spectroscopy

Probst, J.; Braig, Christoph; Langlotz, Enrico; Rahneberg, Ilko; Kühnel, Michael; Zeschke, Thomas; Siewert, Frank; Krist, Thomas; Erko, Alexei

doi:10.1364/ao.384782

Cited by 5 publications

(17 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The correction introduced by a suitable scheme converts an aberrated optics to pseudo-perfect optics which otherwise prevents achieving diffraction-limited focusing. A few schemes such as active bimorph mirrors (Mimura et al, 2010), refractive correctors (Sawhney et al, 2016;Seiboth et al, 2017), invariable-multilayer deposition (Matsuyama et al, 2018), diffractive wavefront correction (Probst et al, 2020) and layer stress controlling method (Cheng & Zhang (2019) have been demonstrated as tools for phase error corrections of different X-ray optical elements. Refraction-based correctors are thin, easy to insert into the beam path, do not change the optical axis and are straightforward to align.…”

Section: Introductionmentioning

confidence: 99%

Correction of the X-ray wavefront from compound refractive lenses using 3D printed refractive structures

Dhamgaye

Laundy

Baldock

et al. 2020

J Synchrotron Radiat

View full text Add to dashboard Cite

A refractive phase corrector optics is proposed for the compensation of fabrication error of X-ray optical elements. Here, at-wavelength wavefront measurements of the focused X-ray beam by knife-edge imaging technique, the design of a three-dimensional corrector plate, its fabrication by 3D printing, and use of a corrector to compensate for X-ray lens figure errors are presented. A rotationally invariant corrector was manufactured in the polymer IP-STM using additive manufacturing based on the two-photon polymerization technique. The fabricated corrector was characterized at the B16 Test beamline, Diamond Light Source, UK, showing a reduction in r.m.s. wavefront error of a Be compound refractive Lens (CRL) by a factor of six. The r.m.s. wavefront error is a figure of merit for the wavefront quality but, for X-ray lenses, with significant X-ray absorption, a form of the r.m.s. error with weighting proportional to the transmitted X-ray intensity has been proposed. The knife-edge imaging wavefront-sensing technique was adapted to measure rotationally variant wavefront errors from two different sets of Be CRL consisting of 98 and 24 lenses. The optical aberrations were then quantified using a Zernike polynomial expansion of the 2D wavefront error. The compensation by a rotationally invariant corrector plate was partial as the Be CRL wavefront error distribution was found to vary with polar angle indicating the presence of non-spherical aberration terms. A wavefront correction plate with rotationally anisotropic thickness is proposed to compensate for anisotropy in order to achieve good focusing by CRLs at beamlines operating at diffraction-limited storage rings.

show abstract

Section: Introductionmentioning

confidence: 99%

Correction of the X-ray wavefront from compound refractive lenses using 3D printed refractive structures

Dhamgaye

Laundy

Baldock

et al. 2020

J Synchrotron Radiat

View full text Add to dashboard Cite

show abstract

“…We suggest using an RZP on a spherical substrate, based on its theoretical description [5]. In comparison with an RZP on a planar substrate, it has evident advances, but is much more difficult to fabricate.…”

Section: Reflection Zone Plate On Curved Substratesmentioning

confidence: 99%

“…The RZPs were fabricated on a spherical substrate with a radius of curvature of 28.617 m. The substrate profile was carefully measured by two different methods, as was reported in [5]. The results, which we used for the correction of the RZP structure from aspheric and local slope (or figure) errors, provided a high spatial resolution.…”

Section: Optical Elementmentioning

confidence: 99%

“…While demonstrating its evident advantages in comparison with conventional VLS gratings, like a high resolving power at the design energy and an excellent signal-to-noise ratio, RZPs on planar substrates suffer from a narrow energy range in parallel spectra registration, limiting the applications of this type of optics. Recent developments in theory, technology, and metrology of RZPs make it possible to fabricate RZPs on spherical substrates with a small radius of curvature down to 2 m. To compensate for the slope error of the substrate, an algorithm for diffractive wavefront correction [5] was used in the calculation of the groove structure.…”

Section: Introductionmentioning

confidence: 99%

“…The concept and theoretical calculations of the RZP properties on spherical or generally figured substrates were published, for example, in the paper [5] and several conference presentations. Unfortunately, up to now, all these theoretical results were not supported by experimental measurements, especially in the soft X-ray range.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Flat Field Soft X-ray Spectrometry with Reflection Zone Plates on a Curved Substrate

Probst¹,

Braig

Erko

2020

Applied Sciences

Self Cite

View full text Add to dashboard Cite

We report on the first experimental results obtained with a newly designed instrument for high-resolution soft X-ray spectroscopy, using reflection zone plates (RZPs) on a spherical substrate. The spectrometer was tested with a fluorescence source. High-resolution flat field spectra within ±50% around the design energies were measured at an interval of 150–750 eV, using only two RZPs: the first RZP, with its design energy of 277 eV, covered the band of 150–370 eV, and the second RZP, with a design energy of 459 eV, covered the band of 350–750 eV, where the upper boundary of this energy range was defined by the Ni coating of the RZPs. The absolute quantum efficiency of the spectrometer, including the optical element and the detector, was, on average, above 10%, and reached 20% at the designed energies of the RZPs. The resolving power E/∆E exceeded 600 for energies E inside the core range of 200–550 eV.

show abstract

Soft X-ray wavefront sensing at an ellipsoidal mirror shell

Braig,

Probst,

Löchel

et al. 2024

J Synchrotron Rad

Self Cite

View full text Add to dashboard Cite

A reliable `in situ' method for wavefront sensing in the soft X-ray domain is reported, developed for the characterization of rotationally symmetric optical elements, like an ellipsoidal mirror shell. In a laboratory setup, the mirror sample is irradiated by an electron-excited (4.4 keV), micrometre-sized (∼2 µm) fluorescence source (carbon K α, 277 eV). Substantially, the three-dimensional intensity distribution I(r) is recorded by a CCD camera (2048 × 512 pixels of 13.5 µm) at two positions along the optical axis, symmetrically displaced by ±21–25% from the focus. The transport-of-intensity equation is interpreted in a geometrical sense from plane to plane and implemented as a ray tracing code, to retrieve the phase Φ(r) from the radial intensity gradient on a sub-pixel scale. For reasons of statistical reliability, five intra-/extra-focal CCD image pairs are evaluated and averaged to an annular two-dimensional map of the wavefront error {\cal W}. In units of the test wavelength (C K α), an r.m.s. value \sigma_{\cal{W}} = ±10.9λ0 and a peak-to-valley amplitude of ±31.3λ0 are obtained. By means of the wavefront, the focus is first reconstructed with a result for its diameter of 38.4 µm, close to the direct experimental observation of 39.4 µm (FWHM). Secondly, figure and slope errors of the ellipsoid are characterized with an average of ±1.14 µm and ±8.8 arcsec (r.m.s.), respectively, the latter in reasonable agreement with the measured focal intensity distribution. The findings enable, amongst others, the precise alignment of axisymmetric X-ray mirrors or the design of a wavefront corrector for high-resolution X-ray science.

show abstract

Conception of diffractive wavefront correction for XUV and soft x-ray spectroscopy

Cited by 5 publications

References 41 publications

Correction of the X-ray wavefront from compound refractive lenses using 3D printed refractive structures

Correction of the X-ray wavefront from compound refractive lenses using 3D printed refractive structures

Flat Field Soft X-ray Spectrometry with Reflection Zone Plates on a Curved Substrate

Soft X-ray wavefront sensing at an ellipsoidal mirror shell

Contact Info

Product

Resources

About