Single-shot diagnostics of laser driven plasma accelerators

We demonstrated single shot diagnostics of laser-plasma accelerators (LPAs). We observed the structure and the evolving process of the blow-out region, the nonlinear waves (plasma bubble) induced by the driving beam using the Faraday rotation diagnostic. We obtained the evolution of the plasma bubble in single shot using Faraday rotation diagnostic with multiple probe beams. The diameter of the bubble changed from 300 μm to 50 μm in 2 cm, which revealed the transition of the acceleration stages from ”bubble expanding mode” to ”bubble stabilizing mode”. Moreover, we demonstrated the broad bandwidth frequency domain streak camera (B-FDSC), which can resolve the dynamics of LPAs in single shot. We improved the temporal resolution of B-FDSC to 10 fs by broadening the bandwidth of the probe beam to 100 nm using supercontinuum generation, and we performed a prototype experiment to show that B-FDSC was capable of resolving the evolution of pulse self-steepening and temporal splitting in a single shot.