We present empirical formulae that provide dispersion and effective area of the fundamental mode in hollow-core antiresonant fibers. The formulae draw on the structural parameters of the fiber and ...allow one to obtain the guiding properties over a wide spectral bandwidth, without the need for time consuming numerical simulations. The formulae are validated by comparing their results with those obtained using the finite-element method. We also analyze the effects of changing the number of antiresonant tubes, as well as adding nested elements in the antiresonant tubes on the guiding properties.
We investigate the effect of the third-order dispersion on higher-order rogue wave solutions. We find that under the presence of weak perturbation, the higher-order rogue wave breaks apart into its ...fundamental rogue wave constituents, similar to how a higher-order soliton undergoes a fission. Each breakaway rogue wave solution is separated in space and time and is accompanied by emission of a dispersive wave.
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We numerically investigate the effect of scaling two key structural parameters in antiresonant hollow-core fibers—dielectric wall thickness of the cladding elements and core size—in view of low-loss ...mid-infrared beam delivery. We demonstrate that there exists an additional resonance-like loss peak in the long-wavelength limit of the first transmission band in antiresonant hollow-core fibers. We also find that the confinement loss in tubular-type hollow-core fibers depends strongly on the core size, where the degree of the dependence varies with the cladding tube size. The loss scales with the core diameter to the power of approximately −5.4 for commonly used tubular-type hollow-core fiber designs.
We show theoretically that the photoionization process in a hollow-core photonic crystal fiber filled with a Raman-inactive noble gas leads to a constant acceleration of solitons in the time domain ...with a continuous shift to higher frequencies, limited only by ionization loss. This phenomenon is opposite to the well-known Raman self-frequency redshift of solitons in solid-core glass fibers. We also predict the existence of unconventional long-range nonlocal soliton interactions leading to spectral and temporal soliton clustering. Furthermore, if the core is filled with a Raman-active molecular gas, spectral transformations between redshifted, blueshifted, and stabilized solitons can take place in the same fiber.
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Complex instabilities are the major reason for drastic changes and extreme events in dynamical systems. Several modes of instability growing simultaneously with nonlinear interaction between them may ...lead to unforeseeable outcomes leading to catastrophic consequences. The most common examples of these instabilities are the modulation instability (MI). Studies show that an infinite number of instability modes remain active in a dynamical system. Although a one-mode MI can be analysed in the frame of a precise mathematical model, namely the Akhmediev breather, the dynamics of several concurrent MI modes referred to as the higher-order MI is very difficult to handle. We developed a unique geometrical approach that provides an entirely new and intuitive way to deal with higher-order MI. We apply this approach in description of higher-order modulation instability, multi-breather solutions, their degenerate versions and higher-order rogue waves of the nonlinear Schrödinger equation. For a system with infinitely many interacting instability modes, the band of the instability in this description is a hypercube, a multi-dimensional space of modulation frequencies. A large variety of special multi-breather and multi-rogue wave solutions of the nonlinear Schrödinger equation in this description corresponds to special points and lines within this hypercube.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
All-solid large-mode-area antiresonant fibers possess unique characteristics of broadband, low-loss transmission of fundamental mode with effective single mode operation. Hinging on the principle, we ...propose a unique hybrid guidance mechanism, combining antiresonant guidance with total internal reflection-based guidance to design bend-tolerant, ultra large mode field area (>3000 µm2) fibers for high-power laser applications. Low-index rods are strategically interspersed into the antiresonant cladding to enhance the modal confinement in the fiber, resulting in lower confinement loss of the fundamental mode and its increased tolerance to bending and to the refractive index dip caused by non-uniform doping of active ions in the fiber core. We show that total internal reflection guidance greatly helps confine the fundamental mode without masking the characteristic features of antiresonant guidance, like effective single mode operation over broad spectral bandwidth. We present a detailed theoretical analysis to design a bendable, effectively single-moded passive and active hybrid-guidance antiresonant fibers, optimized to work in the 1 µm wavelength band. The design principles are universal and can be extended to shift the operating wavelength to the 2 µm range as well.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Prigogine's ideas of systems far from equilibrium and self-organization (Prigogine & Lefever. 1968 J. Chem. Phys. 48, 1695-1700 (doi:10.1063/1.1668896); Glansdorff & Prigogine. 1971 Thermodynamic ...theory of structures, stability and fluctuations. New York, NY/London, UK: Wiley) deeply influenced physics, and soliton science in particular. These ideas allowed the notion of solitons to be extended from purely integrable cases to the concept of dissipative solitons. The latter are qualitatively different from the solitons in integrable and Hamiltonian systems. The variety in their forms is huge. In this paper, one recent example is considered-dissipative solitons with extreme spikes (DSESs). It was found that DSESs exist in large regions of the parameter space of the complex cubic-quintic Ginzburg-Landau equation. A continuous variation in any of its parameters results in a rich structure of bifurcations.
This article is part of the theme issue 'Dissipative structures in matter out of equilibrium: from chemistry, photonics and biology (part 1)'.
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Ultraviolet (UV) generation in the form of the dispersive wave in gas-filled hollow-core fiber is a powerful technique for developing wavelength-tunable ultrafast UV laser. Here, we present a ...numerical investigation examining the influence of the self-steepening effect on UV conversion efficiency. By fine-tuning the self-steepening conditions-reducing the pulse width and employing a longer pump wavelength-we can significantly enhance the conversion efficiency of the generated UV light.
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