Extended Data Fig. 3: Radial metasurface device and resonant excitation.
a, Optical micrograph of a radial metasurface, prepared as a device for photocurrent readout. Inset, radially outward-oriented nanoantennas with resonance at 800 nm and nanoantenna spacing about 500 nm. b, Measured DC photocurrent (dashed line) and simulated plasmonic hotspot field intensity (solid fill; same as in Fig. 1c), verifying the resonantly coupled/enhanced radial photocurrent.
