TY  - CONF
AU  - Mafakheri, Erfan
AU  - Tavabi, Amir Hossein
AU  - Lu, Penghan
AU  - Balboni, Roberto
AU  - Venturi, Federico
AU  - Menozzi, Claudia
AU  - Gazzadi, Gian Carlo
AU  - Frabboni, Stefano
AU  - Boyd, Robert
AU  - Dunin-Borkowski, Rafal
AU  - Karimi, Ebrahim
AU  - Grillo, Vincenzo
TI  - Electron beam lithography for the realization of electron beam vortices with large topological charge ( L=1000ħ)
CY  - Weinheim, Germany
PB  - Wiley-VCH Verlag GmbH & Co. KGaA
M1  - FZJ-2017-01394
SP  - 390 - 391
PY  - 2016
AB  - Electron vortex beams (EVBs) are an appealing topic, both in fundamental science and for practical applications in electron microscopy [1, 2]. Some of the most promising applications require beams that have large orbital angular momentum (OAM) [2, 3, 4]. Here, we demonstrate the largest (L=1000 ħ) high quality EVB by using electron beam lithography (EBL) to fabricate a phase hologram. EBL provides superior fabrication quality and a larger number of addressable points when compared with focused ion beam (FIB) milling. We measure the OAM of the generated EVB through propagation after a hard aperture cut [5]. Comparisons with simulations confirm an average OAM of (960±120)ħ , which is consistent with the intended value.A clear improvement when compared with a FIB-nanofabricated hologram is demonstrated in terms of 1) the maximum OAM that can be reached; 2) the minimum feature size (33 nm in the present study); 3) the improved uniformity of the frequency response; 4) the better suppression of higher order diffraction due to a nearly perfect rectangular groove profile.We believe that EBL will be the fabrication technique of choice for most new diffractive optics with electrons in the future, permitting more complex holograms and new applications in material science.
T2  - 16th European Microscopy Congress (EMC 2016)
CY  - 28 Aug 2016 - 2 Sep 2016, Lyon (France)
Y2  - 28 Aug 2016 - 2 Sep 2016
M2  - Lyon, France
LB  - PUB:(DE-HGF)8 ; PUB:(DE-HGF)7
DO  - DOI:10.1002/9783527808465.EMC2016.5721
UR  - https://juser.fz-juelich.de/record/827196
ER  -