scholarly journals Tunable laser induced periodic surface structures in Ge2Sb2Te5 thin films

2021 ◽  
Vol 2086 (1) ◽  
pp. 012170
Author(s):  
Irina G Bessonova ◽  
Pavel I Trofimov ◽  
Petr I Lazarenko ◽  
Demid A Kirilenko ◽  
Nikolay A Bert ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Change ◽  
Low Cost ◽  
Beam Steering ◽  
Tunable Laser ◽  
Surface Structures ◽  
Periodic Surface ◽  
Light Localization ◽  
Rapid Fabrication ◽  
Direct Laser

Abstract Planar photonic structures, such as gratings and metasurfaces, are routinely used for beam steering, waveguide coupling, and light localization. However, conventional fabrication techniques that involve lithography are demanding in terms of time and cost. Much cheaper and simpler methods for surface patterning and formation of periodic surface structures are enabled by direct laser processing. Here, we demonstrate low-cost rapid fabrication of high-quality phase gratings based on the formation of laser induced periodic surface structures (LIPSS, or ripples) in Ge2Sb2Te5 (GST) thin films. Due to unique phase change properties of GST, the structures demonstrate strong modulation of refractive index with period controlled by the wavelength of laser irradiation. We study the formation of phase change LIPSS in a broad range of excitation wavelengths and observe transition between regimes with different orientations of generated ripples with respect to laser polarization.

scholarly journals Laser induced tunable Ge2Sb2Te5 phase-change gratings

2021 ◽  
Vol 2015 (1) ◽  
pp. 012154
Author(s):  
Pavel I. Trofimov ◽  
Irina G. Bessonova ◽  
Petr I. Lazarenko ◽  
Demid A. Kirilenko ◽  
Nikolay A. Bert ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Change ◽  
Surface Structures ◽  
The Other ◽  
Formation Mechanisms ◽  
Laser Polarization ◽  
Time Cost ◽  
Periodic Surface ◽  
Light Manipulation ◽  
High Flexibility

Abstract Periodic photonic nano- and microstructures are routinely used for light manipulation at the nanoscale. However, their fabrication process is demanding in terms of time, cost and facilities. Here we demonstrate a rapid laser-assisted method for fabrication of gratings in Ge2Sb2Te5 (GST) thin films, based on the formation of laser induced periodic surface structures (LIPSS). LIPSS formation mechanisms dependent on the wavelength of the operating laser, lead to high flexibility of the process, producing gratings with tunable period and orientation with respect to the initial laser polarization. The phase-change properties of GST, on the other hand, allows to fabricate phase gratings with strong modulation of refractive index, which are rewritable in nature.

scholarly journals Laser-induced periodic surface structures on bismuth thin films with ns laser pulses below ablation threshold

2017 ◽  
Vol 7 (6) ◽  
pp. 1777 ◽  
Author(s):  
A. Reyes-Contreras ◽  
M. Camacho-López ◽  
S. Camacho-López ◽  
O. Olea-Mejía ◽  
A. Esparza-García ◽  
...  
Keyword(s):  
Thin Films ◽  
Ablation Threshold ◽  
Laser Pulses ◽  
Surface Structures ◽  
Periodic Surface

scholarly journals Formation of Highly Ordered Platinum Nanowire Arrays on Silicon via Laser-Induced Self-Organization

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1031
Author(s):  
Michael Dasbach ◽  
Hendrik M. Reinhardt ◽  
Norbert A. Hampp
Keyword(s):  
Thin Films ◽  
Nanowire Arrays ◽  
Surface Structures ◽  
Self Organization ◽  
Periodic Patterns ◽  
Periodic Surface ◽  
Platinum Nanowires ◽  
Nanosecond Pulsed Laser ◽  
Sputter Deposited ◽  
20 Nm

Laser-induced periodic surface structures (LIPSS) provide an elegant solution for the generation of highly ordered periodic patterns on the surface of solids. In this study, LIPSS are utilized for the formation of periodic platinum nanowire arrays. In a process based on laser-stimulated self-organization, platinum thin films, sputter-deposited onto silicon, are transformed into nanowire arrays with an average periodicity of 538 nm. The width of the platinum nanowires is adjustable in a range from 20 nm to 250 nm by simply adjusting the thickness of the initial platinum thin films in a range from 0.3 nm to 4.3 nm. With increasing width, platinum nanowires show a rising tendency to sink into the surface of the silicon wafer, thus indicating alloying between platinum and silicon upon LIPSS-formation by a nanosecond-pulsed laser. The Pt/silicon wires may be etched away, leaving a complementary nanostructure in the silicon surface.

scholarly journals Picosecond Laser Interference Patterning of Periodical Micro-Architectures on Metallic Molds for Hot Embossing

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3409 ◽  
Author(s):  
Yangxi Fu ◽  
Marcos Soldera ◽  
Wei Wang ◽  
Bogdan Voisiat ◽  
Andrés Fabián Lasagni
Keyword(s):  
Picosecond Laser ◽  
Processing Parameters ◽  
Hot Embossing ◽  
Surface Structures ◽  
Laser Source ◽  
Laser Interference ◽  
Periodic Surface ◽  
Direct Laser ◽  
Direct Laser Interference Patterning ◽  
532 Nm

In this work, it is demonstrated that direct laser interference patterning (DLIP) is a method capable of producing microtextured metallic molds for hot embossing processes. Three different metals (Cr, Ni, and Cu), relevant for the mold production used in nanoimprinting systems, are patterned by DLIP using a picosecond laser source emitting at a 532 nm wavelength. The results show that the quality and surface topography of the produced hole-like micropatterns are determined by the laser processing parameters, such as irradiated energy density and the number of pulses. Laser-induced periodic surface structures (LIPSS) are also observed on the treated surfaces, whose shapes, periodicities, and orientations are strongly dependent on the accumulated fluence. Finally, the three structured metals are used as embossing molds to imprint microlenses on polymethyl methacrylate (PMMA) foils using an electrohydraulic press. Topographical profiles demonstrate that the obtained structures are comparable to the masters showing a satisfactory reproduction of the texture. The polymeric microlens arrays that showed the best surface homogeneity and overall quality were those embossed with the Cr molds.

Laser-induced modification and formation of periodic surface structures (ripples) of amorphous GST225 phase change materials

2019 ◽  
Vol 113 ◽  
pp. 87-94 ◽  
Author(s):  
Sergey Kozyukhin ◽  
Petr Lazarenko ◽  
Yuri Vorobyov ◽  
Alexander Baranchikov ◽  
Victoria Glukhenkaya ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Surface Structures ◽  
Periodic Surface
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