How Plasmonic excitation influences the LIPSS formation on diamond during multipulse femtosecond laser irradiation ?

Laser Induced Periodic Surface Structure, also called "ripples or nanograting" are part of morphologies that have focused the interest of several researchers and have been on the heart of a lot of studies since the first... [ view full abstract ]

Laser Induced Periodic Surface Structure, also called "ripples or nanograting" are part of morphologies that have focused the interest of several researchers and have been on the heart of a lot of studies since the first experiment done by Birnbaum in 1965 where two types of training LIPSS formation were observed during the irradiation of dielectric, semiconductor and metals by multipulse femtosecond laser linearly polarized, called low spatial frequency LIPSS (LSFL) and high spatial frequency LIPSS (HSFL).

LSFL formation for the majority of materials is well explained by the interference between the incident laser wave and the plasmon polaritons SPP surface. But HSFL formation remain a misunderstood phenomenon and it is still under discussion.

There are several models proposed and many studies were done to identify the origin of formation of this such type of LIPSS on dielectric and semiconductor, induced by multipulse laser femtosecond at low fluency. In such cases, the non-thermal interaction and plasmon excitation play a very important role, where the HSFL's period is very lower to the incident laser wavelength.

A recent explanation of HSFL formation was proposed by Miyazaki et al [1] and Miyaji et al [2] where they proposed that by increasing the number of low fluence pulses, the periodic nanostructures HSFL can be developed through the non-thermal structure change of the treated surface. The nanoscale ablation due to strong near-fields appears around of sweeling followed by a plasmonic excitation (SPP) to improve the nano-periodicity of irradiated area.

In this work, we illustate the plasmon excitation advantage to training HSFL formation through a general plasmon model that can follow the evolution of training LIPSS formation and changing diamond optical parameters in function of electron plasma excitation. We also proposed an hypothesis that can visualize the importance of plasmonic excitation in the dynamic change of non-thermal fusion like an origin of HSFL nanograting periodic training formation.

[1] K. Miyazaki and G. Miyaji, Physics Procedia 39, 674 – 682 ( 2012 ).
[2] G. Miyaji and K. Miyazaki, App. Phys. Lett. 103, 071910 (2013).