Quantum-shot-noise-driven optical antennas

Optical antennas so far have been driven by irradiation of light or by optical pumping of nearby emitters. Electrical driving — as is common for radiowave antennas — has not been possible due to the high frequencies that would be required. We show that electrical driving of an optical antenna is possible via the quantum shot noise that is created by electrons that tunnel across the antenna's atomic scale feedgap. Although the quantum shot noise has a broad frequency distribution, the resulting spectrum of the emitted photons is determined by the antenna resonance and the applied voltage. The spatial pattern and the polarization of the emitted photons is also determined by the antenna geometry.