English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Optimum suppression of higher order modes in single-ring hollow-core photoniccrystal fibers (SR-PCFs) occurs when the capillary-to-core diameter ratio d/D =0.68. Here we report that, in SR-PCFs with sub-optimal values of d/D,higher-order mode suppression can be recovered by spinning the preform duringfiber drawing, thus introducing a continuous helical twist. This geometricallyincreases the effective axial propagation constant (initially too low) of theLP01-like modes of the capillaries surrounding the core, enabling robustsingle-mode operation. The effect is explored by means of extensive numericalmodeling, an analytical model and a series of experiments. Prism-assistedside-coupling is used to investigate the losses and near-field patterns ofindividual fiber modes in both the straight and twisted cases. More than 12dB/m improvement in higher order mode suppression is achieved experimentally ina twisted PCF. The measurements also show that the higher order mode profileschange with twist rate, as predicted by numerical simulations. Helical twistingoffers an additional tool for achieving effectively endlessly single-modeoperation in hollow-core SR-PCFs.

Twist-tuned suppression of higher-order modes in single-ring hollow-core photonic crystal fibers