Surface-plasmon-enhanced multiphoton photoelectric emission from thin silver films

Area of Science:

• Condensed matter physics
• Surface science
• Quantum optics

Background:

• Photoelectric emission is crucial for understanding electron dynamics at surfaces.
• Surface plasmons are collective electron oscillations at metal-vacuum interfaces.
• Multiphoton processes require high laser intensities for electron emission.

Purpose of the Study:

• To investigate the enhancement of multiphoton photoelectric emission using surface plasmons.
• To quantify the increase in quantum yield achieved through this plasmonic enhancement.
• To explore the potential of femtosecond laser-driven surface plasmons for efficient electron emission.

Main Methods:

• Excitation of surface plasmons on a thin silver film using femtosecond laser pulses.
• Utilizing the Kretchmann attenuated-total-internal-reflection (ATR) configuration for resonant pumping.
• Measurement of quantum yield for multiphoton photoelectric emission.

Main Results:

• Observed a significant enhancement of multiphoton photoelectric emission.
• Achieved a quantum yield approaching 2 x 10(-8) for a two-photon process.
• Demonstrated a 5,000-fold increase in quantum yield compared to bulk emission at the same laser fluence.

Conclusions:

• Surface plasmon excitation effectively enhances multiphoton photoelectric emission from thin silver films.
• The Kretchmann ATR configuration provides an efficient method for resonant surface plasmon pumping.
• This plasmon-enhanced emission offers a promising route for high-efficiency electron sources.