journal article·2023-02-01Open access

Automatic Alignment of an Orbital Angular Momentum Sorter in a Transmission Electron Microscope Using a Convolutional Neural Network

Paolo Rosi, Alexander Clausen, Dieter Weber, Amir H. Tavabi, Stefano Frabboni, Peter Tiemeijer, Rafal E. Dunin-Borkowski, Enzo Rotunno, Vincenzo Grillo

Microscopy and Microanalysis· Volume 29· Issue 1

Abstract

Abstract We report on the automatic alignment of a transmission electron microscope equipped with an orbital angular momentum sorter using a convolutional neural network. The neural network is able to control all relevant parameters of both the electron-optical setup of the microscope and the external voltage source of the sorter without input from the user. It can compensate for mechanical and optical misalignments of the sorter, in order to optimize its spectral resolution. The alignment is completed over a few frames and can be kept stable by making use of the fast fitting time of the neural network.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Advanced Electron Microscopy Techniques and Applications · Electron and X-Ray Spectroscopy Techniques · Near-Field Optical Microscopy

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

Istituto Nanoscienze - CNR , via G. Campi 213/A, Modena 41125 , Italy

FIM Department, University of Modena and Reggio Emilia , via G. Campi 213/A, Modena 41125 , Italy

Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich , Jülich 52425 , Germany

Thermo Fisher Scientific , PO Box 80066, KA Eindhoven 5600 , The Netherlands

Funding

DARPA TEE · Deutsche Forschungsgemeinschaft

References (63)

Show source-provided references
1. Abadi · 2016
2. Efficient creation of electron vortex beams for high resolution STEM imaging10.1016/j.ultramic.2016.05.006 ↗
3. Magnetic monopole field exposed by electrons10.1038/nphys2816 ↗
4. Efficient sorting of orbital angular momentum states of light10.1103/PhysRevLett.105.153601 ↗
5. Spatial mode correction of single photons using machine learning10.1002/qute.202000103 ↗
6. Theory and applications of free-electron vortex states10.1016/j.physrep.2017.05.006 ↗
7. FEI titan G2 60-300 HOLO10.17815/jlsrf-2-70 ↗
8. Chaize · 2001
9. Quantitative measurement of orbital angular momentum in electron microscopy10.1103/PhysRevA.89.053818 ↗
10. Symmetry-constrained electron vortex propagation10.1103/PhysRevA.93.063840 ↗
11. Clausen · 2021
12. Chiral nanoemitter array: A launchpad for optical vortices10.1002/lpor.201300117 ↗
13. Decker · 1993
14. Progress in aberration-corrected scanning transmission electron microscopy10.1093/jmicro/50.3.177 ↗
15. Measurement of effective source distribution and its importance for quantitative interpretation of STEM images10.1016/j.ultramic.2010.01.007 ↗
16. A novel method for focus assessment in atomic resolution STEM HAADF experiments10.1016/j.ultramic.2006.03.005 ↗
17. Electron holograms encoding amplitude and phase for the generation of arbitrary wavefunctions10.1017/S1431927615003311 ↗
18. Generation of nondiffracting electron bessel beams
19. Gulli · 2017
20. Measuring the orbital angular momentum of electron beams10.1103/PhysRevA.89.025803 ↗
21. Prerequisites for a Cc/Cs-corrected ultrahigh-resolution TEM10.1016/j.ultramic.2007.07.007 ↗
22. Towards 0.1 nm resolution with the first spherically corrected transmission electron microscope10.1093/oxfordjournals.jmicro.a023610 ↗
23. Electron microscopy image enhanced10.1038/33823 ↗
24. Structured quantum waves10.1038/nphys3404 ↗
25. Stern-Gerlach-like approach to electron orbital angular momentum measurement10.1103/PhysRevA.95.021801 ↗
26. Herbert · ..
27. Machine learning guided rapid focusing with sensor-less aberration corrections10.1364/OE.26.030162 ↗
28. First application of Cc-corrected imaging for high-resolution and energy-filtered TEM10.1093/jmicro/dfp021 ↗
29. Generating optical orbital angular momentum at visible wavelengths using a plasmonic metasurface10.1038/lsa.2014.48 ↗
30. Kingma · 2014
31. Das elektronenmikroskop10.1007/BF01342199 ↗
32. Π/2 mode converters and vortex generators for electrons10.1016/j.ultramic.2019.05.003 ↗
33. Towards sub-Å electron beams10.1016/S0304-3991(99)00013-3 ↗
34. Vibrational spectroscopy in the electron microscope10.1038/nature13870 ↗
35. Nondestructive measurement of orbital angular momentum for an electron beam10.1103/PhysRevLett.117.154801 ↗
36. ‘Twisted’ electrons10.1080/00107514.2017.1418046 ↗
37. Optimization of monochromated TEM for ultimate resolution imaging and ultrahigh resolution electron energy loss spectroscopy10.1016/j.ultramic.2017.08.016 ↗
38. Aberration measurement using the Ronchigram contrast transfer function10.1016/j.ultramic.2010.04.006 ↗
39. Realization of electron vortices with large orbital angular momentum using miniature holograms fabricated by electron beam lithography10.1063/1.4977879 ↗
40. Origins and demonstrations of electrons with orbital angular momentum10.1098/rsta.2015.0434 ↗
41. Efficient sorting of free electron orbital angular momentum10.1088/1367-2630/aa5f6f ↗
42. Efficient separation of the orbital angular momentum eigenstates of light10.1038/ncomms3781 ↗
43. Resolution enhancement in transmission electron microscopy with 60-kV monochromated electron source10.1063/1.4939653 ↗
44. Design of electrostatic phase elements for sorting the orbital angular momentum of electrons10.1016/j.ultramic.2019.112861 ↗
45. Catenary optics for achromatic generation of perfect optical angular momentum10.1126/sciadv.1500396 ↗
46. Autonomous scanning probe microscopy in situ tip conditioning through machine learning10.1021/acsnano.8b02208 ↗
47. Theoretical and practical aspects of the design and production of synthetic holograms for transmission electron microscopy10.1063/5.0067528 ↗
48. Alignment of electron optical beam shaping elements using a convolutional neural network10.1016/j.ultramic.2021.113338 ↗
49. Arbitrary conformal transformations of wave functions10.1103/PhysRevApplied.15.054028 ↗
50. The development of the electron microscope and of electron microscopy10.1007/BF01127674 ↗
51. Measuring the orbital angular momentum of electron vortex beams using a forked grating10.1103/PhysRevLett.111.074801 ↗
52. Measurement method of aberration from Ronchigram by autocorrelation function10.1016/j.ultramic.2008.04.095 ↗
53. Novel vortex generator and mode converter for electron beams10.1103/PhysRevLett.109.084801 ↗
54. Nanostructuring of electron beams10.1088/1402-4896/aaf258 ↗
55. Interferobot: Aligning an optical interferometer by a reinforcement learning agent
56. Generation of electron vortices using nonexact electric fields10.1103/PhysRevResearch.2.013185 ↗
57. Experimental demonstration of an electrostatic orbital angular momentum sorter for electron beams10.1103/PhysRevLett.126.094802 ↗
58. Fabrication of low aspect ratio three-element Boersch phase shifters for voltage-controlled three electron beam interference10.1063/5.0020383 ↗
59. Tiemeijer · 1999
60. Demonstration of a 2 × 2 programmable phase plate for electrons10.1016/j.ultramic.2018.03.017 ↗
61. Shaping electron beams for the generation of innovative measurements in the (S)TEM10.1016/j.crhy.2013.09.014 ↗
62. Automating electron microscopy through machine learning and USETEM10.1017/S1431927621010394 ↗
63. Coma-free alignment of high resolution electron microscopes with the aid of optical diffractograms10.1016/S0304-3991(78)80006-0 ↗