University of Hertfordshire

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By the same authors

Transmission properties of tapered optical fibres: Simulations and experimental measurements

Research output: Contribution to journalArticlepeer-review


  • Piyamas Choochalerm
  • Bill Martin
  • Hugh Jones
  • Ronny Errmann
  • Stephanos Yerolatsitis
  • Thomas Wright
  • Christophe Buisset
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Original languageEnglish
Article number102632
Number of pages8
JournalOptical Fiber Technology
Early online date24 Jul 2021
Publication statusPublished - 1 Oct 2021


We measured the transmission of tapered and untapered optical fibres as a function of input beam numerical aperture at 635 nm. The tapered fibres were fabricated with an adiabatic tapering process from graded and step-index fibres with 50 m core diameters to form a 100 mm long taper with 5:1 taper ratio. We tested tapered graded-index and step-index fibres fabricated from commercial Thorlabs products and a custom graded-index taper. The 5:1 tapered graded-index fibre can give a transmission greater than 0.4 for Thorlabs and 0.6 for the custom taper. We simulated the transmission of the tapered fibres and found reasonable agreement with the measured graded-index tapered fibre results across the numerical aperture range of interest. Experimentally, step-index tapered fibres performed relative poorly and considerably below modelling expectations. Based on our examinations this arises because the properties of step-index fibre were not robust to the tapering process. Suitably tapered graded-index fibres may offer a new route for efficient focal ratio reduction of fibre optic signals, e.g., in fibre-fed spectrographs, though we stress that our measurements have been limited to monochromatic light in this work.


© 2021 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license.

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