Analysis of laser absorption on a rough metal surface

Abstract

We have developed a simple model to estimate the cumulative absorption coefficient of an ultraviolet laser pulse impinging on a pure metal, including the effects of surface roughness whose scale is much larger than the laser wavelength. The multiple reflections from the rough surface may increase the absorption coefficient over a pristine, flat surface by an order of magnitude. Thus, as much as 16% ͑at room temperature͒ of the power of a 248 nm KrF excimer laser pulse may be absorbed by an aluminum target. A comparison with experimental data is given.

A selective laser melting and solution heat treatment refined Al–12Si alloy with a controllable ultrafine eutectic microstructure and 25% tensile ductility

“…However, many factors such as the size and morphology of the powder particles, the surface and roughness of the samples will influence the actual absorption co-efficient of a material. In general, the laser absorption for a powder sample is 3-5 times higher than a thin film sample with the same composition [36,37]. Therefore, in this work, the absorption co-efficient was set to 20%.…”

A comprehensive study of infrared reflectivity of poly(3,4-ethylenedioxythiophene) model layers with different morphologies and conductivities

“…Such a behavior of conducting PEDOT layers can be compared to that of metallic surfaces. Indeed, their surface roughness significantly influences their optical properties due to scattering phenomena [57][58][59][60][61]. Both experimental and theoretical studies have been conducted to assess the absorption coefficient of rough metal surfaces.…”

Research on acoustical properties of the femtosecond laser ablation targets using fiber optic sensing probe

“…Under the same laser conditions, the absorbing laser energy is different for the metals of different electrical conductivity. The absorption coefficient (in power) [15] could be expressed as:…”