Hierarchical anti-reflective laser-induced periodic surface structures (LIPSSs) on amorphous Si films for sensing applications

Abstract

<p>Unique hierarchical laser-induced periodic surface structures (LIPSSs) enable the detection of metal ions at sub-nM concentrations <italic>via</italic> surface-enhanced fluorescence.</p>

Controlling the wettability of stainless steel from highly-hydrophilic to super-hydrophobic by femtosecond laser-induced ripples and nanospikes

“…Due to the conned laser-matter interaction area, the ultrashort laser pulses gives a possibility to reach a precise structuring in the scale of micrometres by direct laser writing technique via ablation. Surface structuring by ultrashort pulses is possible even below the light diffraction limit due to generation of selforganised structures like laser-induced periodic surface structures (LIPSS) 11,[16][17][18] and nanoparticles. 10,19 The usage of stainless steel surfaces with altered wetting properties is wide and could be applied for many applications.…”

Crystallization of optically thick amorphous silicon films by near-IR femtosecond laser processing

“…Such a modulation oriented along the polarization vector was justified to originate from interference of the incident and scattered laser radiation. The surface morphology modification (typically oxidation, [34]) is known to start at interference maxima where laser intensity Laser-modified α-Si film areas processed at optimal parameters demonstrate changed optical properties, which can be seen in optical reflection and transmission images (Fig. 1b).…”

“…The resulting intensity distribution in the focal plane presented elliptically shaped beam with a size of 160 µm along long axis and the axes ratio of 1:10. Based on our previous studies [34], pulse energy and scanning speed were chosen to be 1.5 µJ and 1 mm/s, respectively.…”

Direct Femtosecond Laser Fabrication of Chemically Functionalized Ultra-Black Textures on Silicon for Sensing Applications

“…Such a behavior could be indicative of defocusing of the incident laser beam via filamentation in liquid. For a fixed pulse repetition rate (κ = 1 KHz), larger beam size was found to increase spatial overlap between adjacent pulses on the Si surface, which facilitated LIPSS formation through the improved positive feedback [33,34]. The orientation of formed LIPSS was found to be perpendicular with respect to the polarization vector of the second-pass laser beam.…”

“…The thickness of attached layers is usually on the order of several nanometers, which requires sufficiently sensitive equipment when optical chemosensors are used. In this work, a thin fluorescent layer was attached to a nano-textured substrate, which, as was shown earlier [34,37], provides a significant enhancement of PL emission that can be easily detected by standard equipment. Noteworthily, dielectric structures are advantageous for the realization of the sensors based on PL enhancement effects.…”