Generation and application of bessel beams in electron microscopy

Area of Science:

• Electron optics
• Holography
• Materials science

Background:

• Electron Bessel beams offer unique properties for advanced microscopy.
• Precise control over electron beam generation is crucial for high-resolution imaging and interferometry.

Purpose of the Study:

• To systematically investigate the holographic generation of electron Bessel beams.
• To optimize the process for high efficiency and controllable beam characteristics.
• To explore applications in electron microscopy and interferometry.

Main Methods:

• Detailed theoretical modeling of hologram patterning.
• Experimental setup using a specific electron-optical configuration.
• Nanofabrication optimization for hologram creation.
• Characterization of generated electron Bessel beams, including phase structure.

Main Results:

• Achieved relative efficiencies of electron Bessel beam generation up to 37±3%.
• Demonstrated control over beam localization by tuning hologram parameters, enabling applications in imaging and interferometry.
• Successfully controlled beam convergence and topological charges.
• Characterized phase structure, accounting for fabrication imperfections.

Conclusions:

• The developed holographic technique provides an efficient and controllable method for generating electron Bessel beams.
• The ability to tune beam properties makes this technique versatile for various electron microscopy and interferometric applications.
• Further optimization of nanofabrication can enhance beam quality and generation efficiency.