Abstract
We exploit free-space interactions between electron beams and tailored light fields to imprint on-demand phase profiles on the electron wave functions. Through rigorous semiclassical theory involving a quantum description of the electrons, we show that monochromatic optical fields focused in vacuum can be used to correct electron beam aberrations and produce selected focal shapes. Stimulated elastic Compton scattering is exploited to imprint the required electron phase, which is proportional to the integral of the optical field intensity along the electron path and depends on the transverse beam position. The required light intensities are attainable in currently available ultrafast electron microscope setups, thus opening the field of free-space optical manipulation of electron beams.
Highlights
Electron microscopy has experienced impressive advances over the last decades thanks to the design of sophisticated magnetostatic and electrostatic lenses that reduce electron optics aberrations [1,2,3] and are capable of focusing electron beams (e-beams) with subångstrom accuracy [4, 5]
Plates with individually-biased perforations have been developed to enable position-selective control over the electric Aharonov-Bohm phase stamped on the electron wave function [14], while passive carved plates have been employed as amplitude filters to produce highly-chiral electron vortices [15,16,17] and aberration correctors [18, 19]
In this Letter, we propose an optical free-space electron modulator (OFEM) in which a phase profile is imprinted on the transverse electron wave function by means of stimulated elastic Compton scattering associated with the A2 term in the light-electron coupling
Summary
Electron microscopy has experienced impressive advances over the last decades thanks to the design of sophisticated magnetostatic and electrostatic lenses that reduce electron optics aberrations [1,2,3] and are capable of focusing electron beams (e-beams) with subångstrom accuracy [4, 5]. We have proposed to use PINEM to imprint on-demand transverse e-beam phase profiles [59], relying on ultrafast e-beam shaping as an alternative approach to aberration correction. This method enables fast active control over the modulated e-beam at the expense of retaining only ∼ 1/3 of monochromatic electrons and potentially introducing decoherence through inelastic interactions with the light scatterer. While optical ebeam phase stamping has been demonstrated using a continuous-wave laser in a tour-de-force experiment [60], we envision pulsed illumination as a more feasible route to implement an OFEM, exploiting recent advances in ultrafast electron microscopy, in systems that incorporate light injection with high numerical aperture [50] for diffraction-limited patterning of the optical field
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
