Topology optimization of on-chip integrated laser-driven particle accelerator

Particle accelerators are indispensable tools in both science and industry. However, the size and cost of conventional RF accelerators limits the utility and scope of this technology. Recent research has shown that a dielectric laser accelerator (DLA) made of dielectric structures and driven at optical frequencies can generate particle beams with energies ranging from MeV to GeV at the tabletop level. To design DLA structures with a high acceleration gradient, we demonstrate topology optimization, which is a method used to optimize the material distribution in a specific area based on given load conditions, constraints, and performance indicators. To demonstrate the effectiveness of this approach, we propose two schemes and design several acceleration structures based on them. The optimization results demonstrate that the proposed method can be applied to structure optimization for on-chip integrated laser accelerators, producing manufacturable structures with significantly improved performance compared with previous size or shape optimization methods. These results provide new physical approaches to explore ultrafast dynamics in matter, with important implications for future laser particle accelerators based on photonic chips.