Nonlinear laser absorption on metal surfaces embedded with metallic nanoparticles and nanotubes

Abstract

The nonlinear absorption of a short laser on metal surfaces, embedded with metallic nanoparticles and nanotubes, is studied theoretically. The absorption is resonantly enhanced by the surface plasmon resonance where the laser frequency becomes comparable to the frequency of surface charge oscillations. Heat conduction inside the metal limits the rise in electron temperature. The absorption coefficient increases with the angle of incidence for all frequencies. For expanding clusters, the heating rate rises with time, attaining a sharp maximum at the instant when the plasmon resonance occurs. Beyond this time, the electron temperature falls due to thermal conduction. Similar effects are observed in the case of carbon nanotubes.

Nonlinear laser absorption on metal surface embedded with nanoparticles in the presence of external magnetic field

“…We have plotted normalized absorption coefficient F versus normalized frequency 3 It is evident from figure 2 that the absorption coefficient increases with the increase in magnetic field strength. Absorption coefficient for the said metal nanostructures has been shown by Yadav et al [38] in the absence of magnetic field. But on the application of external magnetic field, the electrons of the nanoparticles get excited and exhibit resonant plasma oscillations.…”

“…And, it has also been investigated for different incident angles and different magnetic field strengths. The approach is similar to the problem of nonlinear laser absorption under similar configuration by Yadav et al [38]. However, the nature of the problem is totally different.…”