Extended Data Fig. 2: FEL spectra versus seed delay.
From: Seeded free-electron laser driven by a compact laser plasma accelerator
Seed delay scan.a,b. Average FEL spectra versus seed delay. c,d. Average FEL differential signal ΔFEL(λ) (FEL spectra with seed subtraction) versus seed delay. b,d. Spectra for three seed delays: -0.66 ps (red), -0.16 ps (blue), and 0.34 ps (green). Black dashed line (a,d): analytical model for FEL wavelength red shift. Vertical dotted lines (b): bandwidth for integration of the FEL and seed intensity.
