Figure 3: Laser controllable tunability of the focus intensity.

(a) Normalized focusing intensities of GO lenses fabricated at increasing laser powers from 1.5 to 8 μW (black spheres). Theoretical prediction (red solid line) shows remarkable agreements with the experimental results. The error bar is based on the statistical average by sampling GO lenses with the identical fabrication power. Insets: Cross-sectional intensity distributions in the lateral direction of two GO lenses fabricated at 3 and 7 μW, respectively. Scale bar, 1 μm. (b) The prepared large size 200-nm-thick GO thin film on a glass substrate. (c) Two sets of GO lenses following the contours of an Australian map and a kangaroo are patterned in a 1.5 mm² area (dashed circle in b). (d) Schematic diagram of focusing of the GO lenses under a plane wave illumination (white arrows). (e) Measured microscopic images of the contours of an Australian map and a kangaroo at the lens focusing plane showing different focusing intensities. Scale bar, 200 μm.