Periodic structure of different dielectric layers for dielectric laser accelerators

Abstract

In this paper, a periodic structure of different dielectric layers is proposed and investigated for relativistic electron acceleration. The periodic dielectric structure provides an accelerating electric field inside the structure. Results show that the electron beam can experience a strong electric force in one direction during propagation in the structure, leading to the acceleration gradient increasing by more than double in comparison with dual-grating structures. Acceleration gradient enhancement occurs without increasing the electric field much inside the structure; therefore, the maximum achievable acceleration gradient and acceleration factor are increased by more than 100%, reaching 0.7. Thereby, by using the proposed structure GV/m, the acceleration gradient can be achieved with a wide electron channel. Also, the required input laser fluence is reduced for the same acceleration gradient. Acceleration gradient and acceleration factor optimization is done corresponding to structure parameters. Our work shows that the proposed structure helps to make dielectric laser accelerators more efficient.

Efficiently accelerated free electrons by metallic laser accelerator

“…In recent years, because of the high laser damage thresholds of dielectric materials [3][4][5] , dielectric laser accelerators (DLAs) have been studied in many laboratories [6][7][8] . To achieve high acceleration gradients, various nanostructures (e.g., dual pillar gratings, distributed Bragg re ectors) [9][10][11][12] have been designed and many new techniques (including the pulse-fronttilted laser and multiple driving) [13][14][15] have been developed. However, the required acceleration gradient on the gigavolt per metre scale has not been realized by DLA to date, and the exploration of new laser-driven accelerator designs continues.…”

Efficiently accelerated free electrons by metallic laser accelerator

“…In recent years, because of the high laser damage thresholds of dielectric materials [3][4][5] , dielectric laser accelerators (DLAs) have been studied in many laboratories [6][7][8] . To achieve high acceleration gradients, various nanostructures (e.g., dual pillar gratings, distributed Bragg reflectors) [9][10][11][12] have been designed and many new techniques (including the pulse-front-tilted laser and multiple driving) [13][14][15] have been developed. Though the driving fields have reached 9 GV/m for the DLA 16,17 , yielding the highest average acceleration gradient to date, the ratio between the average acceleration gradient and the incident laser field is still low.…”