Figure 4
Laser pulse energy dependence of corona discharge power (a) and of FGCD induced fluorescence intensity (b).
The fluorescence intensity in (b) was calculated by integrating the pixel intensity of the streamers in the rectangular areas as shown in the inset figure from the FGCD images in Fig. 3. Each pair of rectangles was separated so as to avoid including the direct contribution of the light coming from the on-axis filament zone.
