Abstract
Ponderomotive electron acceleration is demonstrated in a semiconductor-loaded nanoplasmonic waveguide. Photogenerated free carriers are accelerated by the tightly confined nanoplasmonic fields and reach energies exceeding the threshold for impact ionization. Broadband () white light emission is observed from the nanoplasmonic waveguides. Exponential growth of visible light emission confirms the exponential growth of the electron population, demonstrating the presence of an optical-field-driven electron avalanche. Electron sweeping dynamics are visualized using pump-probe measurements, and a sweeping time of is measured. These findings offer a means to harness the potential of the emerging field of ultrafast nonlinear nanoplasmonics.
- Received 15 January 2014
DOI:https://doi.org/10.1103/PhysRevLett.113.167401
© 2014 American Physical Society