Microspheres Formation in a Glass–Metal Hybrid Fiber System: Application in Optical Microwires

Abstract

Multicomponent optical fibers with incorporated metals are promising photonic platforms for engineering of tailored plasmonic structures by laser micromachining or thermal processing. It has been observed that during thermal processing microfluidic phenomena lead to the formation of embedded micro- and nanostructures and spheres, thus triggering the technological motivation for their theoretical investigation, especially in the practical case of noble metal/glass composites that have not yet been investigated. Implemented microwires of gold core and glass cladding, recently studied experimentally, are considered as a reference validation platform. The Plateau-Rayleigh instability in such hybrid fibers is theoretically investigated by inducing surface tension perturbations and by comparing them to the Tomotika instability theory. The continuous-core breakup time was calculated via Finite Element Method (FEM) simulations for different temperatures and was found to be considerably higher to Tomotika’s model, while the final sphere diameter is a linear function of the initial core radius. Different sinusoidal perturbation parameters were considered, showing significant impact in the characteristics of formed spherical features. The theoretical results were in close agreement with previous experimental observations expected to assist in the understanding of the processes involved, providing insight into the engineering of fibers, both in the initial drawing process and post processing.

Multimaterial fiber as a physical simulator of a capillary instability

“…MS1: The cladding-to-air interface of the fiber is not significantly prone to capillary instability; thus, the cladding can be considered of an infinitely large diameter. It allows us to suggest that the model is valid for tapered-cladding geometries 40 , recently acquiring technological relevance. We have verified experimentally (see Supplementary Note 9 ) that AVG-IM is valid for adiabatically tapered geometries of both core and cladding.…”

Bioinspired Plateau–Rayleigh Instability on Fibers: From Droplets Manipulation to Continuous Liquid Films

“…[1,[7][8][9][10] Such fundamental instability underlies a range of fascinating phenomena and has shown versatile applications, such as fluidic coating, micro-patterning, and materials fabrication, in which the liquid jets are decomposed into the arranged droplets for making mono-dispersed droplets/particles and the periodic fibrous structures with adjustable sizes. [1,[11][12][13][14][15][16] On the other hand, the PRI also manifests in the fluid film on a single fiber which is intrinsically unstable as well and spontaneously breaks up into a periodic array of droplets (Figure 1C). [17] As the typical open system, fibers, especially those with topological structures, have demonstrated various abilities in liquid manipulation, which therefore has attracted significant research attention.…”