Probing of a surface plasma wave by an obliquely incident laser on the metal surface

Abstract

A surface plasma wave ͑SPW͒ of frequency 1 and wave number k 1 propagating along a metal-free space boundary exerts a ponderomotive force on the free electrons, creating an electron density perturbation at frequency 2 1. When a laser of frequency 2 and wave number k 2 is incident at a suitable angle on the metal surface, it gives rise to the oscillatory velocity of electrons at frequency 2. This oscillatory velocity couples with the density perturbation to generate a nonlinear current at frequency 2 1 + 2. The nonlinear current derives a radiating wave under suitable conditions. By measuring the amplitude of the radiating wave, the SPW field can be probed.

Modeling of terahertz radiation emission from a free‐electron laser

“…At lower values of frequency, the effect of the pump amplitude is not noticeable, but as the frequency increases, the power increases with the increase in the amplitude of the pump field. This result is in line with the theoretical investigation of Singh et al Figure shows that the frequency of the emitted THz radiation increases with the wiggler wave vector, and from the relations and (where λ 0 is the wiggler period and λ 1 is the emitted radiation wavelength), the wiggler period decreases with the increase in wiggler wave vector, and consequently the frequency of the output radiation can be increased by reducing the wiggler period.…”

“…Singh et al studied the excitation of SPW by using a laser incident obliquely on the free space interface and observed that the power of the output radiation can be increased monotonically by increasing the frequencies of the laser and the SPW field.…”

Surface plasma wave assisted second harmonic generation of laser over a metal film

“…Recently, SPW induced harmonic generation and other nonlinear effects from metallic surfaces have attracted significant attention. [21][22][23][24][25][26][27][28][29][30][31] Li et al 32 carried out simulations to investigate plasmon gap modeassisted third-harmonic generation from metal film coupled nanowires. The plasmon gap resonance enhances the third harmonic intensity by four orders of magnitude.…”