Dynamic phase-driven inverse Smith-Purcell dielectric laser accelerator on a chip

Pursuing on-chip particle accelerators has long been a focal point for researchers, and the inverse Smith-Purcell dielectric laser accelerator holds great promise as a viable option. However, achieving the cascade acceleration and focusing of subrelativistic electrons on a chip remains one of the most formidable challenges. In this paper, we propose a dynamic phase method to address this issue. This method takes advantage of the phase slippage between the electron and the acceleration wave, enabling transverse alternate focusing, defocusing, and continuous acceleration. Simulation results show that a 29.50 keV electron beam with a 20 eV spread can achieve an acceleration gradient of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mn>39</a:mn> <a:mtext> </a:mtext> <a:mtext> </a:mtext> <a:mi>MV</a:mi> <a:mo>/</a:mo> <a:mi mathvariant="normal">m</a:mi> </a:mrow> </a:math> with a captured efficiency of 95% within a 120-μm distance in a 200-nm-wide channel. Compared with the alternating phase method, this approach streamlines the fabrication process by removing the need for incremental adjustments of the phase velocity at each accelerating stage to match the electron energy. We anticipate that applying the dynamic phase-driven approach will significantly propel the development of on-chip accelerators.