Observation of few-cycle, strong-field phenomena in surface plasmon fields

Area of Science:

• * Plasmonics and ultrafast optics.
• * Surface science and electron emission phenomena.

Background:

• * Surface plasmon polaritons (SPPs) are electromagnetic waves propagating at metal-dielectric interfaces.
• * Generating ultrashort SPP pulses is crucial for high-resolution surface studies and advanced applications.

Purpose of the Study:

• * To experimentally demonstrate the generation of few-cycle propagating surface plasmon polariton wavepackets.
• * To investigate the potential of these ultrashort plasmonic pulses for electron emission and acceleration.

Main Methods:

• * Generation of few-cycle (2-3 oscillations) SPP wavepackets.
• * Characterization using autocorrelation measurements via electron photoemission.
• * Demonstration of plasmon-induced electron emission and acceleration.

Main Results:

• * Successful generation and characterization of few-cycle SPP wavepackets.
• * Achieved plasmon-induced tunneling emission at low laser intensity due to field enhancement.
• * Demonstrated all-optical electron acceleration up to keV kinetic energy with low focused laser intensity (1.35×10^12 W/cm²).

Conclusions:

• * Experimental evidence confirms the generation of few-cycle SPP wavepackets.
• * These ultrashort plasmonic pulses offer a promising platform for strong-field experiments with reduced pulse energies.
• * The findings pave the way for novel applications in ultrafast electron dynamics and surface science.