Low-loss single-mode hybrid-lattice hollow-core photonic-crystal fibre

Abstract

Remarkable recent demonstrations of ultra-low-loss inhibited-coupling (IC) hollow-core photonic-crystal fibres (HCPCFs) established them as serious candidates for next-generation long-haul fibre optics systems. A hindrance to this prospect and also to short-haul applications such as micromachining, where stable and high-quality beam delivery is needed, is the difficulty in designing and fabricating an IC-guiding fibre that combines ultra-low loss, truly robust single-modeness, and polarisation-maintaining operation. The design solutions proposed to date require a trade-off between low loss and truly single-modeness. Here, we propose a novel IC-HCPCF for achieving low-loss and effective single-mode operation. The fibre is endowed with a hybrid cladding composed of a Kagome-tubular lattice (HKT). This new concept of a microstructured cladding allows us to significantly reduce the confinement loss and, at the same time, preserve truly robust single-mode operation. Experimental results show an HKT-IC-HCPCF with a minimum loss of 1.6 dB/km at 1050 nm and a higher-order mode extinction ratio as high as 47.0 dB for a 10 m long fibre. The robustness of the fibre single-modeness is tested by moving the fibre and varying the coupling conditions. The design proposed herein opens a new route for the development of HCPCFs that combine robust ultra-low-loss transmission and single-mode beam delivery and provides new insight into IC guidance.

Large-scale two-photon calcium imaging in freely moving mice

“…Moreover, while the current miniscope enables recording from more than a thousand neurons at a time, pulse-multiplexing technology (Cheng et al, 2011) and adaptive optics (Ji, 2017; Wang et al, 2014) will undoubtedly increase the cell yield further. New types of hollow-core photonic crystal fibers will allow multi-wavelength excitation, increasing the options for choices of indicator (Amrani et al, 2021), and 2P miniscope imaging will be fused with optogenetic stimulation technology (Emiliani et al, 2015; Marshel et al, 2019), enabling large-scale mapping of connectivity between functionally characterized neurons not only in virtual-reality setups but also during unrestrained behavior. By open-sourcing protocols and software for assembly and use of the new miniscope, we hope that a growing number of investigators will be involved in the further development of large-scale high-resolution imaging in freely behaving rodents.…”

Study on the High-Birefringence Hollow-Core Anti-Resonant Fiber with Semicircular Cladding

“…With the advancement of optical fiber manufacturing technology, especially the development of technology for hypocycloid-core Kagome fiber [23,24] and negative curvature fiber [25,26], it should be feasible to draw multilayer ARF. Similar hollow fibers have been made by stacking and stretching processes [27].…”

Azimuthal Fourier Decomposition for Loss Analysis of Hollow-Core Tube Lattice Fibers Part II: Tube Thickness Variation Effects

“…H OLLOW core photonic crystal fibers (HCPCF) based on Inhibited Coupling (IC) waveguiding mechanism, exhibit very attractive properties such as wide transmission bandwidth, low loss, low dispersion, and a relatively simple cladding structure. In the last few years, IC guiding HCPCF (IC-HCPCF) with Tube Lattice cladding (TLF) have experienced an impressive transmission loss reduction [1]- [5]. However, a gap remains between the experimentally measured loss and the theoretically achievable minimum defined by confinement loss (CL) [6], [7].…”