Metallic nanoparticles grown in the core of femtosecond laser micromachined waveguides

Abstract

Articles you may be interested inEr:Yb-doped oxyfluoride silicate glass waveguide amplifier fabricated using femtosecond laser inscription Appl. Phys. Lett. 90, 131102 (2007) 3D-waveguides containing silver nanoparticles have been fabricated in tungsten leadpyrophosphate glass by femtosecond laser micromachining. Nucleation and growth of nanoparticles occur in a single step process when high repetition rate laser (MHz) is employed, while an additional annealing is required for the irradiation using kHz laser system. The presence of nanoparticles locally changes the refractive index, and, therefore, the elliptical structures produced by direct laser writing were able to guide light. By increasing the pulse energy applied during the micromachining, the waveguide size increased from 2 to 30 lm, while their propagation loss decrease from 1.4 to 0.5 dB/mm at 632.8 nm. V C 2014 AIP Publishing LLC.

Ultrafast Laser Pulses for Structuring Materials at Micro/Nano Scale: From Waveguides to Superhydrophobic Surfaces

“…Therefore, the control of nanoparticle precipitation in very confined regions by fs-laser micromachining might be an important advance towards the development of metamaterials for all-optical devices. The growth of metallic NPs in the core of femtosecond-laser micromachined waveguides was recently demonstrated [36], according to the optical microscopy images in Figure 13. It has been discussed that the formation of Ag NPs, along with the waveguide fabrication, helps to improve the refractive index change, since an increase of 4.6% (or ∆n = 0.07) has been reported due to the presence of silver NPs in silicate glasses [113].…”

“…Cations in the glass matrix can react with these free electrons resulting in their reduction. Therefore, if the glass is doped with, for instance, Ag + , Au 3+ , Cu 2+ ions, photoreduction reactions promote the formation of neutral atoms that further aggregate on account of the atomic mobility provided by the increase of temperature [35,36,107]. …”

“…Therefore, if the glass is doped with, for instance, Ag + , Au 3+ , Cu 2+ ions, photoreduction reactions promote the formation of neutral atoms that further aggregate on account of the atomic mobility provided by the increase of temperature [35,36,107]. This procedure is summarized through Equations (1)- (3), which elucidate the formation of metallic silver nanoparticles by femtosecond-laser micromachining [36,108]. The same mechanism can be applied to other metals; nonetheless, one must consider the number of electrons involved in the photoreduction reaction.…”

“…The scale bar for (b,c) is the same of (a). Reprinted with permission from [36]. Copyright (2014), AIP Publishing LLC.…”

“…multi-photon absorption). Because the multi-photon absorption is localized into the focal volume, the resulting structural changes [33,34], photoreduction [35,36], degradation [37] and ablation [38], will also be confined to the vicinity of the focus, which can be exploited to advance materials processing.…”