Based on the scalar Helmholtz equation and the finite-difference approximation, we formulate a matrix eigenvalue problem for the calculation of propagation constants, beta(omega), in micro-structured optical fibres. The method is applied to index-guiding fibres as well as air-core photonic bandgap fibres, and in both cases qualitatively correct results are found. The strength of this approach lies in its very simple numerical implementation and its ability to find eigenmodes at a specific eigenvalue, which is of great interest, when modelling defect modes in photonic bandgap fibres.
In hydrodynamics, vortex generation upon the transition from smooth laminar flows to turbulence is generally accompanied by increased dissipation. However, plane vortices can provide transport barriers and decrease losses, as it happens in numerous geophysical, astrophysical flows and in tokamaks. Photon interactions with matter can affectlight transportin waveguides in unexpected and somewhat counterintuitive ways resembling fluid dynamics. Here, we demonstrate dramatic impact of light vortex formation in micro-structured optical fibres on the energy dissipation. We show possibility of vortic…
Micro-combs [1 - 4], optical frequency combs generated by integrated micro-cavity resonators, offer the full potential of their bulk counterparts [5,6], but in an integrated footprint. The discovery of temporal soliton states (DKS dissipative Kerr solitons) [4,7-11] as a means of modelocking microcombs has enabled breakthroughs in many fields including spectroscopy [12,13], microwave photonics [14], frequency synthesis [15], optical ranging [16,17], quantum sources [18,19], metrology [20,21] and more. One of their most promising applications has been optical fibre communications where they hav…
Optomagnetic forces on YIG/YFeO3 microspheres levitated in chiral hollow-core photonic crystal fibre
Friedrich-Alexander-Universität Erlangen-Nürnberg（埃尔朗根-纽伦堡大学）；Max Planck Institute for the Science of Light（马克斯·普朗克光科学研究所）；Institute of Particle Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg（埃尔朗根-纽伦堡大学颗粒技术研究所）；Interdisciplinary Center for Functional Particle Systems, Friedrich-Alexander-Universität Erlangen-Nürnberg（埃尔朗根-纽伦堡大学功能粒子系统跨学科中心）；RWTH Aachen University（亚琛工业大学）；Institute for Theoretical Solid-State Physics, RWTH Aachen University（亚琛大学理论固体物理学研究所）；Institute of Micro- and Nanostructure Research and Center for Nanoanalysis and Electron Microscopy, Friedrich- Alexander-Universität Erlangen-Nürnberg（埃尔朗根-纽伦堡大学微纳结构研究中心及纳米分析与电子显微镜中心）
Compact Photonic Fibre-based Deformation Sensor Fabricated by Two-Photon Polymerization
Aston Institute of Photonic Technologies, Aston University（阿斯顿光子技术研究所，阿斯顿大学）；Laser nanoFab GmbH（激光纳米制造有限公司）；Leibniz Universität Hannover（汉诺威莱布尼茨大学）；Bruker Nano GmbH（布鲁克纳米有限公司）
Holographic wavefront manipulation enables converting hair-thin multimode optical fibres into minimally invasive lensless imaging instruments conveying much higher information densities than conventional endoscopes. Their most prominent applications focus on accessing delicate environments, including deep brain compartments, and recording micrometre-scale resolution images of structures in close proximity to the distal end of the instrument. Here, we introduce an alternative 'farfield' endoscope, capable of imaging macroscopic objects across a large depth of field. The endoscope shaft with dim…
Optical soliton dynamics can cause the extreme alteration of the temporal and spectral shape of a propagating light pulse. They occur at up to kilowatt peak powers in glass-core optical fibres and the gigawatt level in gas-filled microstructured hollow-core fibres. Here we demonstrate optical soliton dynamics in large-core hollow capillary fibres. This enables scaling of soliton effects by several orders of magnitude to the multi-mJ energy and terawatt peak power level. We experimentally demonstrate two key soliton effects. First, we observe self-compression to sub-cycle pulses and infer the c…
A systematic numerical study of ultrafast nonlinear directional coupler performance based on soliton self-trapping in a novel type of dual-core optical fibre is presented. The considered highly nonlinear fibre structure is composed of a real, intentionally developed soft glass-pair with high refractive index contrast at the level of 0.4 in the near infrared. Nonlinear propagation of picojoule level femtosecond pulses was studied numerically with the aim to identify the best switching performance in input parameter space of 1400 - 1800 nm in terms of excitation wavelengths, and of 75 - 150 fs i…
Online measurement of diameters and concentricities of optical fibre layers, and the coating layer in particular, is one of the challenges in fibre manufacturing. Currently available instruments can measure concentricity and diameter of layers offline, and are not suitable for precise monitoring or control of the manufacturing process in real time. In this work, we use two laser beams, positioned orthogonally to illuminate the fibre from two sides, and calculate deviations from the expected geometry by analysing the scattering pattern. To measure the diffraction pattern we use two 8K linear ar…
The optical fibre is an essential tool for our communication infrastructure since it is the main transmission channel for optical communications. The latest major advance in optical fibre technology is spatial division multiplexing (SDM), where new fibre designs and components establish multiple co-existing data channels based on light propagation over distinct transverse optical modes. Simultaneously, there have been many recent developments in the field of quantum information processing (QIP), with novel protocols and devices in areas such as computing, communication and metrology. Here, we …
