Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Compact high-resolution differential interference contrast soft x-ray microscopy
KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Biomedicinsk fysik och röntgenfysik.
Vise andre og tillknytning
2008 (engelsk)Inngår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 92, nr 064104Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

We demonstrate high-resolution x-ray differential interference contrast (DIC) in a compact soft x-ray microscope. Phase contrast imaging is enabled by the use of a diffractive optical element objective which is matched to the coherence conditions in the microscope setup. The performance of the diffractive optical element objective is evaluated in comparison with a normal zone plate by imaging of a nickel siemens star pattern and linear grating test objects. Images obtained with the DIC optic exhibit typical DIC enhancement in addition to the normal absorption contrast. Contrast transfer functions based on modulation measurements in the obtained images show that the DIC optic gives a significant increase in contrast without reducing the spatial resolution. The phase contrast operation mode now available for our compact soft x-ray microscope will be a useful tool for future studies of samples with low absorption contrast.

sted, utgiver, år, opplag, sider
2008. Vol. 92, nr 064104
Emneord [en]
diffractive optical-elements, zone plates, phase-contrast, fabrication, condenser
HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-9811DOI: 10.1063/1.2842422ISI: 000253237900123Scopus ID: 2-s2.0-39349084101OAI: oai:DiVA.org:kth-9811DiVA, id: diva2:133154
Merknad
QC 20100728Tilgjengelig fra: 2009-01-07 Laget: 2009-01-07 Sist oppdatert: 2017-12-14bibliografisk kontrollert
Inngår i avhandling
1. Nanofabrication of Diffractive Soft X-ray Optics
Åpne denne publikasjonen i ny fane eller vindu >>Nanofabrication of Diffractive Soft X-ray Optics
2009 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

This thesis summarizes the present status of the nanofabrication of diffractive optics, i.e. zone plates, and test objects for soft x-ray microscopy at KTH. The emphasis is on new and improved fabrication processes for nickel and germanium zone plates. A new concept in which nickel and germanium are combined in a zone plate is also presented. The main techniques used in the fabrication are electron beam lithography for the patterning, followed by plasma etching and electroplating for the structuring of the optical materials. The process for fabricating nickel zone plates has been significantly improved. The reproducibility of the electroplating step has been increased by the implementation of an in-situ rate measurement and an end-point detection method. We have also shown that pulse plating can be used to obtain zone plates with a uniform height profile. New plating mold materials have been introduced and electron-beam curing of the molds has been investigated and implemented to increase their mechanical stability so that pattern collapse in the electroplating step can be avoided. The introduction of cold development has improved the achievable resolution of the process. This has enabled the fabrication of zone plates with outermost zone widths down to 16 nm. The nickel process has also recently been adapted to fabrication of gold structures intended for test objects and hard x-ray zone plates. For the fabrication of germanium zone plates we developed a highly anisotropic plasma-etch process using Cl2 feed and sidewall passivation. Germanium zone plates have been fabricated with zone widths down to 30 nm. The diffraction efficiency is comparable to that of nickel zone plates, but the process does not involve electroplating and thus has for potential for highyield fabrication. The combination of nickel and germanium is a new fabrication concept that provides a means to achieve high diffraction efficiency even for thin nickel. The idea is to fabricate a nickel zone plate on a germanium film. The nickel zone plate itself is then used as etch mask for a highly selective CHF3- plasma etch into the germanium layer. Proof of principle experiments showed an efficiency increase of about a factor of two for nickel zone plates with a 50- nm nickel thickness.

sted, utgiver, år, opplag, sider
Stockholm: KTH Royal Institute of Technology, 2009. s. vii, 71
Serie
Trita-FYS, ISSN 0280-316X ; 2008:57
Emneord
Nanofabrication, Zone plate, x-ray, diffractive x-ray optics, x-ray microscopy
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-9800 (URN)978-91-7415-205-0 (ISBN)
Disputas
2009-02-06, FR4, Roslagstullsbacken 21, Stockholm, 10:00 (engelsk)
Opponent
Veileder
Merknad
QC 20100728Tilgjengelig fra: 2009-01-13 Laget: 2009-01-07 Sist oppdatert: 2011-10-20bibliografisk kontrollert
2. Phase-Contrast and High-Resolution Optics for X-Ray Microscopy
Åpne denne publikasjonen i ny fane eller vindu >>Phase-Contrast and High-Resolution Optics for X-Ray Microscopy
2010 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

X-ray microscopy is a well-established technique for nanoscale imaging. Zone plates are used as microscope objectives and provide high resolution, approaching 10 nm, currently limited by fabrication issues. This Thesis presents zone plate optics that achieve either high resolution or phase contrast in x-ray microscopy. The high-resolution optics use high orders of the zone plate, which alleviates the demands on fabrication, and the phase-contrast optics are single-element diffractive optical elements that produce contrast by Zernike or differential-interference contrast methods. The advantage of phase contrast in x-ray microscopy is shorter exposure times, and is crucial in the hard x-ray regime. Microscopy in the absorption‑contrast region of the water-window (2.34 - 4.37 nm) also benefits from these optics. The development of the optics for a laboratory soft x-ray microscope spans from theoretical and numerical analysis of coherence and stray light to experimental implementation and testing. The laboratory microscope uses laser-produced plasma-sources in the water-window and is unique in its design and performance. It will be shown that the laboratory microscope in its current form is a user-oriented and stable instrument, and has been used in a number of applications. The implementation of a cryogenic sample stage for tomographic imaging of biological samples in their natural environment has enabled applications in biology, and 3D x-ray microscopy of cells was performed for the first time with a laboratory instrument.

 

sted, utgiver, år, opplag, sider
Stockholm: KTH, 2010. s. x, 61
Serie
Trita-FYS, ISSN 0280-316X ; 72
Emneord
Microscopy, X-ray optics, X-ray microscopy, Soft X-ray physics
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-26781 (URN)978-91-7415-834-2 (ISBN)
Disputas
2010-12-17, FD5, Roslagstullsbacken 21, Stockholm, 15:42 (engelsk)
Opponent
Veileder
Merknad
QC 20101130Tilgjengelig fra: 2010-11-30 Laget: 2010-11-26 Sist oppdatert: 2010-11-30bibliografisk kontrollert
3. Laboratory soft x-ray microscopy and tomography
Åpne denne publikasjonen i ny fane eller vindu >>Laboratory soft x-ray microscopy and tomography
2011 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Soft x-ray microscopy in the water-window (λ = 2.28 nm – 4.36 nm) is based on zone-plate optics and allows high-resolution imaging of, e.g., cells and soils in their natural or near-natural environment. Three-dimensional imaging is provided via tomographic techniques, soft x-ray cryo tomography. However, soft x-ray microscopes with such capabilities have been based on large-scale synchrotron x‑ray facilities, thereby limiting their accessibility for a wider scientific community.

This Thesis describes the development of the Stockholm laboratory soft x-ray microscope to three-dimensional cryo tomography and to new optics-based contrast mechanisms. The microscope relies on a methanol or nitrogen liquid-jet laser-plasma source, normal-incidence multilayer or zone-plate condenser optics, in-house fabricated zone-plate objectives, and allows operation at two wavelengths in the water-window, λ = 2.48 nm and λ = 2.48 nm. With the implementation of a new state-of-the-art normal-incidence multilayer condenser for operation at λ = 2.48 nm and a tiltable cryogenic sample stage the microscope now allows imaging of dry, wet or cryo-fixed samples. This arrangement was used for the first demonstration of laboratory soft x-ray cryo microscopy and tomography. The performance of the microscope has been demonstrated in a number of experiments described in this Thesis, including, tomographic imaging with a resolution of 140 nm, cryo microscopy and tomography of various cells and parasites, and for studies of aqueous soils and clays. The Thesis also describes the development and implementation of single-element differential-interference and Zernike phase-contrast zone-plate objectives. The enhanced contrast provided by these optics reduce exposure times or lowers the dose in samples and are of major importance for harder x-ray microscopy. The implementation of a high-resolution 50 nm compound zone-plate objective for sub-25-nm resolution imaging is also described. All experiments are supported by extensive numerical modelling for improved understanding of partially coherent image formation and stray light in soft x-ray microscopes. The models are useful tools for studying effects of zone plate optics or optical design of the microscope on image formation and quantitative accuracy in soft x-ray tomography.

sted, utgiver, år, opplag, sider
Stockholm: KTH Royal Institute of Technology, 2011. s. x, 76
Serie
Trita-FYS, ISSN 0280-316X ; 2011:03
Emneord
Microscopy, X-ray optics, Diffractive optics, Zone plates, X-ray microscopy, Soft X-ray physics, Tomography
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-29950 (URN)978-91-7415-874-8 (ISBN)
Disputas
2011-02-25, FB42, AlbaNova Universitetscentrum, Roslagstullsbacken 21, Stockholm, 13:00 (engelsk)
Opponent
Veileder
Merknad
QC 20110221Tilgjengelig fra: 2011-02-21 Laget: 2011-02-18 Sist oppdatert: 2011-02-21bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekstScopushttp://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=APPLAB000092000006064104000001&idtype=cvips&gifs=yes

Personposter BETA

Hertz, Hans M.Vogt, Ulrich

Søk i DiVA

Av forfatter/redaktør
Bertilson, Michaelvon Hofsten, OlovLindblom, MagnusHertz, Hans M.Vogt, Ulrich
Av organisasjonen
I samme tidsskrift
Applied Physics Letters

Søk utenfor DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric

doi
urn-nbn
Totalt: 260 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf