E. L. Ginzton Laboratory, Stanford University, Stanford, CA, USA.
SLAC National Accelerator Laboratory, Menlo Park, CA, USA.
Science. 2020 Jan 3;367(6473):79-83. doi: 10.1126/science.aay5734.
Particle accelerators represent an indispensable tool in science and industry. However, the size and cost of conventional radio-frequency accelerators limit the utility and reach of this technology. Dielectric laser accelerators (DLAs) provide a compact and cost-effective solution to this problem by driving accelerator nanostructures with visible or near-infrared pulsed lasers, resulting in a 10 reduction of scale. Current implementations of DLAs rely on free-space lasers directly incident on the accelerating structures, limiting the scalability and integrability of this technology. We present an experimental demonstration of a waveguide-integrated DLA that was designed using a photonic inverse-design approach. By comparing the measured electron energy spectra with particle-tracking simulations, we infer a maximum energy gain of 0.915 kilo-electron volts over 30 micrometers, corresponding to an acceleration gradient of 30.5 mega-electron volts per meter. On-chip acceleration provides the possibility for a completely integrated mega-electron volt-scale DLA.
粒子加速器是科学和工业中不可或缺的工具。然而，传统射频加速器的尺寸和成本限制了这项技术的实用性和应用范围。介电激光加速器（Dielectric Laser Accelerators，DLAs）通过使用可见光或近红外脉冲激光驱动加速器纳米结构，解决了这一问题，其规模缩小了 10 倍。目前的 DLA 实现依赖于直接入射到加速结构上的自由空间激光，限制了这项技术的可扩展性和集成性。我们展示了一种基于光子逆向设计方法设计的波导集成 DLA 的实验演示。通过将测量的电子能谱与粒子追踪模拟进行比较，我们推断出在 30 微米的距离内最大能量增益为 0.915 千电子伏特，对应的加速梯度为 30.5 兆电子伏特/米。片上加速为完全集成的兆电子伏特规模 DLA 提供了可能性。
