Fig. 2: Transient electron-gas lensing images.
From: Transient lensing from a photoemitted electron gas imaged by ultrafast electron microscopy
Series of 3000 mesh copper grid images (b) and difference images (a) extracted from a ps-resolved UEM movie (528 nm, 200 fs, 30 mJ/cm2 laser excitation) with an objective lens current of 0.7 A. The time delays correspond to the first few local maxima and minima in the ROI difference intensity trace in Fig. 3. The difference images were generated by subtracting an averaged image before time zero (Δt = 0). A typical region-of-interest (ROI) circle that is used to make plots of the intensity changes due to lensing is indicated in the last frame. The scale bar at the bottom right is 50 μm and applies to all images. The intermediate lens current was set to 0.65 A.
