Possible surface plasmon polariton excitation under femtosecond laser irradiation of silicon

TL;DR

This paper investigates how femtosecond laser pulses induce ripple structures on silicon surfaces by exploring the transient free-carrier dynamics and conditions for surface plasmon polariton excitation, enabling better control of laser-induced surface patterns.

Contribution

It reveals the conditions for surface plasmon polariton excitation on silicon under femtosecond laser irradiation and analyzes how laser parameters influence ripple periodicity.

Findings

Identified conditions for surface plasmon polariton excitation.

Analyzed ripple period dependence on laser parameters.

Provided insights for controlling laser-induced surface structures.

Abstract

The mechanisms of ripple formation on silicon surface by femtosecond laser pulses are investigated. We demonstrate the transient evolution of the density of the excited free-carriers. As a result, the experimental conditions required for the excitation of surface plasmon polaritons are revealed. The periods of the resulting structures are then investigated as a function of laser parameters, such as the angle of incidence, laser fluence, and polarization. The obtained dependencies provide a way of better control over the properties of the periodic structures induced by femtosecond laser on the surface of a semiconductor material.