Wavelength-scalable hollow optical fibres with large photonic bandgaps for CO2 laser transmission

Abstract

Conventional solid-core optical fibres require highly transparent materials. Such materials have been difficult to identify owing to the fundamental limitations associated with the propagation of light through solids, such as absorption, scattering and nonlinear effects. Hollow optical fibres offer the potential to minimize the dependence of light transmission on fibre material transparency. Here we report on the design and drawing of a hollow optical fibre lined with an interior omnidirectional dielectric mirror. Confinement of light in the hollow core is provided by the large photonic bandgaps established by the multiple alternating submicrometre-thick layers of a high-refractive-index glass and a low-refractive-index polymer. The fundamental and high-order transmission windows are determined by the layer dimensions and can be scaled from 0.75 to 10.6 micro m in wavelength. Tens of metres of hollow photonic bandgap fibres for transmission of carbon dioxide laser light at 10.6 micro m wavelength were drawn. The transmission losses are found to be less than 1.0 dB m(-1), orders of magnitude lower than those of the intrinsic fibre material, thus demonstrating that low attenuation can be achieved through structural design rather than high-transparency material selection.

In-Fiber Semiconductor Filament Arrays

“…[35], [36]. In order to achieve low-loss omnidirectional reflectivity in the iD finite periodic structure shown in figure 3-2a, necessary conditions must be met on large contrast of refractive index nH/nL and on the ratio of the lower index to the ambient nL/nA.…”

“…c, SEM micrograph of the fiber cross-section is shown on the left, and a magnified section of the intact semiconductor thin film, right, confirms that the layered structure is preserved. In order to demonstrate the new opportunities of these multifunctional fibers, hollow-core PBG transmission fiber will be taken as an example [36]. Most widely used conventional silica fibers transmit light through a solid core of doped silica (SiO2) glass using the mechanism of index confinement, or total internal reflection.…”

“…Recent work, however, has generalized optical fiber manufacturing to include microstructured fibers that combine multiple distinct materials including metals, semiconductors, and insulators, which expand fiber-device functionalities while retaining the simplicity of the thermal-drawing fabrication approach [77]. For example, a periodic cylindrical-shell multilayer structure has been incorporated into a fiber to guide light in a hollow core with significantly reduced loss for laser surgery [82]. Ideally, the cross-section of the resulting fibers retains the same structure and relative sizes of the components as in the preform.…”

Smelling in Chemically Complex Environments: An Optofluidic Bragg Fiber Array for Differentiation of Methanol Adulterated Beverages

“…By thermal drawing of the preform, hollow-core photonic band gap fibers of extended length and desired band gaps were produced. 29,30 Analyte Preparation. Ethanol, methanol, and water solutions with different volume percentages were prepared in plastic vials.…”

Optofluidic waveguides: II. Fabrication and structures

“…Bragg fibers have been made in a number of ways. One method involved the deposition of As 2 Se 3 layers onto poly(ether sulphone) (PES) films Temelkuran et al 2002). These films were rolled into a hollow multilayer tube that acted as a preform.…”