Analysis of mirror soft-x-ray–EUV scattering using generalized continuous growth model of multiscale reliefs

Goray, Leonid I.; Lubov, M. N.

doi:10.1364/oe.23.010703

Cited by 16 publications

(14 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In this case the shadowing effect in the classical orientation is overcome by the 'transparency' of the multilayer coating. The related high diffraction efficiencies also for finepitch gratings (Voronov et al, 2015(Voronov et al, , 2016 can be reliably calculated theoretically (Gorai, 2005;Goray & Egorov, 2016). It goes beyond the scope of the present study to discuss more details of this approach.…”

Section: Figurementioning

confidence: 71%

“…In the code PCGrates, which is based on the MIM, the earlier discovered peculiarity is used in the case of gratings and rough mirrors (e.g. Goray & Lubov, 2015) working at very small /p: Introducing known speed-up terms in integral methods produces an adverse numerical effect because of the ensuing uncontrolled growth of coefficients in analytically improved asymptotic estimations (Goray & Sadov, 2002). In that case, however, the profile depth, the bi-layer thickness (for multilayer gratings) and the radiation wave- General schematic of diffraction from a periodic structure for a wavefield with two orthogonal field components for an arbitrary angle of incidence and polarization.…”

Section: Exact Electromagnetic Theory For Very Small Wavelength-to-pementioning

confidence: 99%

“…In order to account for rigorous random surfaces in the X-ray range we use an infinite beam (plane wave) and assume that the random rough surface length repeats itself for a given large-period grating having a number of random asperities. This classical model implies using infinite grating samples together with intensive Monte Carlo computations (Goray & Lubov, 2015;Goray & Schmidt, 2014).…”

Section: Exact Electromagnetic Theory For Very Small Wavelength-to-pementioning

confidence: 99%

See 2 more Smart Citations

Rigorous calculations and synchrotron radiation measurements of diffraction efficiencies for tender X-ray lamellar gratings: conical versus classical diffraction

2018

Self Cite

View full text Add to dashboard Cite

When reflection gratings are operated at grazing incidence in the extreme offplane configuration and the incident beam trajectory is parallel to the grooves, the diffraction into the first order can be more efficient than in the classical orientation. This situation is referred to as the conical diffraction case. In the classical configuration the grooves are perpendicular to the incident beam and thus an efficiency-reducing shadowing effect will be observed at very grazing angles. It was recently shown that a laminar grating could provide symmetric and relatively high efficiencies in conical diffraction for diffraction even of photons with large energies of the order of 4 and 6 keV. For photon energies in the tender X-ray range, accurate computing tools for the calculation of diffraction efficiencies from gratings with simple coatings have not been available. Promising results for this spectral range now require the development of tools for modelling the diffraction efficiency expected in optical instrumentation, in which the provision of high efficiency in the indicated spectral range is mandatory. This is the case when weak sources are to be investigated, like in space science. In this study it will be shown that scalar calculations are not appropriate for this purpose, while newly introduced rigorous calculations based on the boundary integral equation method, implemented in the PCGrate 1 code, can provide predictions that are in agreement with observed diffraction efficiencies. The agreement is achieved by modelling the exact surface profile. This applies for both the conical diffraction configuration and for the classical inplane configuration, in which a significantly lower efficiency was obtained. Even though the profile of the presented grating was not perfect, but significantly distorted, the calculations show that efficiency-wise the structure provided already more than 75% of the ideally expected efficiency for conical diffraction. This is a very promising result for further optimization of diffraction gratings for use in the tender X-ray range. research papers J. Synchrotron Rad. (2018). 25, 1683-1693 Goray, Jark and Eichert Diffraction efficiencies for tender X-ray lamellar gratings 1685 research papers 1690 Goray, Jark and Eichert Diffraction efficiencies for tender X-ray lamellar gratingsFigure 8Comparison of the measured grating efficiencies for a photon energy of 4 keV ( = 0.307 nm) for different orders (zeroth to third) in the conical diffraction scheme as measured by Jark & Eichert (2015) with the calculations using the rigorous approach accounting for the real grating profile (solid line). The prediction by the scalar theory is shown by the dashed line.

show abstract

Section: Figurementioning

confidence: 71%

Section: Exact Electromagnetic Theory For Very Small Wavelength-to-pementioning

confidence: 99%

Section: Exact Electromagnetic Theory For Very Small Wavelength-to-pementioning

confidence: 99%

See 1 more Smart Citation

Rigorous calculations and synchrotron radiation measurements of diffraction efficiencies for tender X-ray lamellar gratings: conical versus classical diffraction

2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…Deformation of the boundary profiles in the case of strong smoothing can transform the saw-tooth profile into a sinusoidal one (Voronov et al, 2011b). Deposition noise not only affects the root-meansquare surface roughness but also leads to the evolution of the initial surface topography into a complex structure characterized by a set of roughnesses and correlation lengths (Senthilkumar et al, 2005;Yashchuk et al, 2014;Goray & Lubov, 2015). Nonlocal effects can significantly transform the grating boundaries, since a local growth event occurring at some point on the profile surface influences the growth process at a great distance from the original event.…”

Section: Introductionmentioning

confidence: 99%

“…For the first time, to the best of our knowledge, this integrated approach was proposed by Goray & Lubov (2013) to calculate the absolute efficiencies of multilayer Mo/Si and Al/Zr gratings, working in the extreme ultraviolet range. This approach was also successfully applied to the consideration of the growth of rough multilayer mirrors and the calculation of scattering intensities in the soft X-ray and extreme ultraviolet ranges (Goray & Lubov, 2015). The use of this approach allowed the shift and deformation of the profile during the growth of Al/Zr gratings to be explained (Voronov et al, 2011a,b).…”

Section: Introductionmentioning

confidence: 99%

High-efficiency X-ray multilayer-coated blazed gratings with shifted boundaries

Lubov

Goray

2019

J Synchrotron Radiat

Self Cite

View full text Add to dashboard Cite

A new design for a high‐efficiency multilayer‐coated blazed X‐ray grating with horizontal‐shifted (non‐conformal) boundary profiles is proposed. The investigation of the grating design is carried out using an integrated approach based on rigorous numerical calculations of light diffraction by gratings with realistic boundary profiles obtained from simulations of multilayer grating growth. By varying the incidence angle of the deposition flux, one can set the direction and magnitude of the boundary profile shifts over a wide range of values. It is shown that the diffraction efficiency of the blazed gratings with shifted boundary profiles may be substantially higher than the efficiency of gratings with conformal boundaries, which are, moreover, much more difficult to produce. High‐efficiency gratings with shifted boundaries can be obtained when the deposition is mainly on the blaze facet with a high inclination of the deposition flux, as opposed to widely used near‐normal deposition methods. The maximum absolute efficiency of a W/B4C 2500 mm−1 grating with a blaze angle of 1.76° and an anti‐blaze angle of 20°, working at a blaze wavelength of 1.3 nm and having shifted realistic boundary profiles, obtained using our integrated approach is 23.3%, while that of a grating with the ideal (triangular) boundary profile and the same shifts is 25.3%, and that of an ideal conformal profile is only 22.2%. The maximum absolute efficiency of 40.2% of a 2500 mm Cr/C grating with a blaze angle of 1.05° and a realistic anti‐blaze angle of 10°, working at a blaze wavelength of 0.83 nm and having ideal shifted boundaries, is higher than the maximum efficiency of the similar grating having ideal conformal boundaries with a non‐realistic anti‐blaze angle of 80°.

show abstract

Fine characterization of MBE-grown super-multiperiod AlGaAs/GaAs superlattices designed for THz radiation sources

Goray,

Pirogov,

Sobolev

et al. 2024

Materials Science in Semiconductor Processing

View full text Add to dashboard Cite

Analysis of mirror soft-x-ray–EUV scattering using generalized continuous growth model of multiscale reliefs

Cited by 16 publications

References 22 publications

Rigorous calculations and synchrotron radiation measurements of diffraction efficiencies for tender X-ray lamellar gratings: conical versus classical diffraction

Rigorous calculations and synchrotron radiation measurements of diffraction efficiencies for tender X-ray lamellar gratings: conical versus classical diffraction

High-efficiency X-ray multilayer-coated blazed gratings with shifted boundaries

Fine characterization of MBE-grown super-multiperiod AlGaAs/GaAs superlattices designed for THz radiation sources

Contact Info

Product

Resources

About