► Black silicon is produced by direct femtosecond laser surface structuring. ► In the visible, the reflectance of the blackened surface is less than 5%. ► Low reflectance of black silicon extends to ...mid-infrared wavelengths. ► Created black silicon is mechanically robust.
Using a direct femtosecond laser surface structuring technique, an array of equally spaced parallel nanostructure-textured microgrooves on silicon was produced that causes a dramatic reduction of the treated silicon reflectance. The processed area appears velvet black at all viewing angles. Throughout the visible region, the reflectance of the blackened surface is less than 5%. The antireflection effect of the processed surface also extends to the mid-infrared wavelength range. Furthermore, this technique has a potential in reducing silicon reflectance at terahertz frequencies and even in millimeter wavelength range.
In this study we perform the first femtosecond laser surface treatment of titanium in order to determine the potential of this technology for surface structuring of titanium implants. We find that ...the femtosecond laser produces a large variety of nanostructures (nanopores, nanoprotrusions) with a size down to 20
nm, multiple parallel grooved surface patterns with a period on the sub-micron level, microroughness in the range of 1–15
μm with various configurations, smooth surface with smooth micro-inhomogeneities, and smooth surface with sphere-like nanostructures down to 10
nm. Also, we have determined the optimal conditions for producing these surface structural modifications. Femtosecond laser treatment can produce a richer variety of surface structures on titanium for implants and other biomedical applications than long-pulse laser treatments.
Following direct femtosecond laser pulse irradiation, we produce a unique grating structure over a large area superimposed by finer nanostructures on a silicon wafer. We study, for the first time, ...the antireflection effect of this femtosecond laser-induced periodic surface structures (FLIPSSs) in the wavelength range of 250 - 2500 nm. Our study shows that the FLIPSSs suppress both the total hemispherical and specular polarized reflectance of silicon surface significantly over the entire studied wavelength range. The total polarized reflectance of the processed surface is reduced by a factor of about 3.5 in the visible and 7 in the UV compared to an untreated sample. The antireflection effect of the FLIPSS surface is broadband and the suppression stays to the longest wavelength (2500 nm) studied here although the antireflection effect in the infrared is weaker than in the visible. Our FLIPSS structures are free of chemical contamination, highly durable, and easily controllable in size.
Using high-intensity femtosecond laser pulses, we create a novel surface pattern that transforms regular silicon to superwicking. Due to the created surface structure, water sprints vertically uphill ...in a gravity defying way. Our study of the liquid motion shows that the fast self-propelling motion of water is due to a supercapillary effect from the surface structures we created. The wicking dynamics in the produced surface structure is found to follow the classical square root of time dependence.
In this paper, we report on various nanostructures produced through direct surface modification on metals using femtosecond laser pulses. We show, for the first time, that these nanosctructures are ...natural consequence following femtosecond laser ablation. The optimal conditions for producing various nanostructures are determined.
The purpose of this article is to identify possible approaches to the development of an Organizational sustainability conceptual model and to present this model for discussion by the expert ...community. To achieve this goal, the author suggests defining the structure and description of individual elements of sustainability, as well as establishing the relationship between them. The sustainability model will serve as a conceptual basis for the development of international and national standards aimed at certain aspects of organizational sustainability, will assist organizations in developing and implementing sustainability strategies and goals, managing ESG factors and associated risks and opportunities, as well as preparing non-financial reporting.
By applying the femtosecond laser blackening technique directly to a tungsten incandescent lamp filament, we dramatically brighten the tungsten lamp and enhance its emission efficiency to approach ...100%. A comparison study of emission and absorption for the structured metal surfaces shows that Kirchhoff's law is applicable for the black metal. Furthermore, we demonstrate that we can even obtain partially polarized light as well as control the spectral range of the optimal light emission from the laser-blackened tungsten lamp.
This report presents a project of an experiment for precision studies of the elastic electron proton scattering in the low momentum transfer region. The project is based on an innovative experimental ...method which allows for detection of recoil protons in a hydrogen “active target”. The goal of the experiment is to measure the
ep
elastic scattering differential cross section in the
Q
2
range from 0.001 to 0.04 GeV
2
with 0.1% relative and 0.2% absolute precision and to determine the proton charge radius with a sub-percent precision. The important advantages of the proposed experiment are low radiative corrections, inherent to the recoil proton method, and absolute measurements of the differential cross sections. The experiment will be performed in the 720 MeV electron beam of the Mainz electron accelerator MAMI. This accelerator can provide an electron beam with optimal for this experiment parameters. The Proposal was approved by the MAMI Program Advisory Committee, and a special Agreement aimed at realization of this experiment was signed between Petersburg Nuclear Physics Institute and Institute of Nuclear Physics of the Mainz University. Also, scientists from the following institutes will participate in this project: GSI Centre for Heavy Ion Research, Germany; Joint Institute for Nuclear Research, Russia; William and Mary College, USA; Mount Allison University, Canada; University of Regina, Canada; Saint Mary’s University, Canada. The first measurements should be started in 2020.
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