Fig. 5: Polarization-controlled directional photoemission. | Nature Communications

Fig. 5: Polarization-controlled directional photoemission.

From: Plasmonic nanostar photocathodes for optically-controlled directional currents

Fig. 5

a Experimental nanostar polarization dependence at 775 nm with nearly equal contributions from both nanostar tip resonances. Tip hot spots are selected by rotating linear polarization while keeping frequency constant, as demonstrated in the calculations on and between the resonances. b Experimental and c theoretical vz-projected velocity maps for the different polarizations at constant frequency. Vectors indicate the peak directions determined by Gaussian fits around the peaks of the angular distributions. Peak photoemission angles range from 55° (50°) at 50° linear polarization aligned along the short tip to 310° (315°) at 315° linear polarization aligned along the long tip, for the experimental (theoretical) velocity distributions. The vector magnitude represents the velocity of photoelectrons excited from the Fermi level (vF), which remains constant for all distributions due to the fixed excitation frequency.

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