Photon-recycling dielectric laser accelerator

TL;DR

This paper introduces a photon-recycling dielectric laser accelerator using silicon photonics, which efficiently accelerates electrons with low-power light and can also function as an electron energy filter, advancing integrated quantum electron optics.

Contribution

The work presents a novel photon-recycling DLA system with an adaptive algorithm for optimizing waveguide structures, achieving high acceleration gradients and broad energy manipulation capabilities.

Findings

High photon utilization in optimized DLA loop

Efficient low-power electron acceleration

Broad energy range electron filtering

Abstract

We propose a photon-recycling dielectric laser accelerator (DLA) system based on silicon photonic device. Our DLA system employs guided electromagnetic waves as a primary energy source, modulated to inject into the electron-light interaction region to accelerate or modulate electron beams and recycled the energy for the next round-trip. Long-distance acceleration takes place as electrons interact with the pre-modulated light field. Our loop recycles post-interaction light field, enabling photons reuse across successive cycles. To optimize the interaction process, we developed an adaptive algorithm to refine waveguide structures, and identified an "optimal waveguide accelerator" with superior performance on our dataset. We find that the optimized DLA loop only requires low-power light injection to sufficiently sustain high acceleration gradients for continuous electron beams. Under optimal electron beam intensity, the system achieves exceptionally high photon utilization, ensuring that nearly all injected light power transferred to electrons. Using spectral analysis, we demonstrate that the optimal waveguide also operates as an electron energy filter, selecting and manipulating phase-matched electrons over a broad energy range, even for quantum electron wavefunction shaping. Our photon-recycling DLA setup is not only suitable for low-energy beam accelerators, but also offers versatility as a beam filter or a narrow energy selection combined with other optical elements, the total setup can be further applied to explore free electron quantum optics engaging with the advancing field of photonic integrated circuits.