Formation of high-aspect-ratio protrusions on gold films by localized pulsed laser irradiation

Direct laser printing of chiral plasmonic nanojets by vortex beams

“…Finally, the similarity of our present observations and the previous extensive experience in fabrication of thinfilm nanojets, using short-and ultrashort laser pulses [24][25][26]30], provokes us to compare formation of the nonand chiral nanoneedles. In comparison to previously reported results [10,17], where no nanojets were observed under irradiation of the bulk metal target with the zero-OAM Gaussian pulses, for silver films studied in this paper, both Gaussian-and donut-shaped beams produce nanojets, having non-and chiral shapes, respectively.…”

“…2(A-D)) illustrates the formation and evolution of the twisted nanojets produced under single-pulse irradiation of the 500-nm thick Ag film, covering the silica glass substrate, with ns-laser vortex pulse focused at NA=0.3. Besides the evident twisted shape of the produced nanojets with their clockwise rotational symmetry (the sign of vortex helicity), expectedly coinciding with the vortex pulse handedness, their formation process appears to be very similar to that for common nanojets fabricated under single-pulse ablation of noble (semi-noble) metal films with Gaussian-shape (zero-OAM) ns-laser pulses [21][22][23][24][25][26]. The main energy-resolved steps include (i) accumulation of the molten material at the spatial center of the beam through thermocapillary forces and melt flows, which rapidly thin the peripheral part, (ii) formation of the liquid nanojet, which undergoes a Rayleigh-Plateau hydrodynamic instability, resulting in appearance and ejection of the molten droplets and, finally, (iii) formation of the through hole by breaking the significantly thinned area, surrounding the nanojet, at increased pulse energy (this stage is not shown in the SEM images).…”

“…Finally, the chirality of the nanojets decreases versus NA. In more general words, the chiral nanojets produced under high-NA focusing (NA=0.65) become less twisted (averaged number of the turnovers per single nanojet decreases) and more similar to those produced under zero-OAM Gaussian pulse ablation [21][22][23][24][25][26]. In particular, this can indicate that the formation process is directly connected with the resolidification time, which is expectedly smaller for the structures produced under the tight focusing conditions.…”

Plasmon Mode Excitation and Photoluminescence Enhancementon Silver Nanorin

“…Однако использование указанных методов требует применения дорогостояще-го высокотехнологичного оборудования, зачастую недоступного ши-рокому кругу исследователей. Существуют, однако, технологически гораздо более простые лазерные методы модификации поверхностей, которые уже продемонстрировали возможность создания широкой но-менклатуры функциональных наноструктур [9][10][11][12][13][14][15][16][17]. В настоящей рабо-те будет показано, что использование таких методов в сочетании с по-следующим реактивным ионным травлением позволяет изготавливать изолированные кольцевые серебряные наноструктуры с контролируе-мыми геометрическими размерами на диэлектрической подложке.…”

Focused ion beam milled pattern structures induced by laser pulse on AgInSbTe phase change films

“…Micro/nano-structuring of surfaces of various materials is the main trend in recent industrial applications [4]. Laser direct-writing technology has made great progress in obtaining surface structures with spatial resolution exceeding the optical diffraction limit due to many advantages [5][6].…”