Abstract
We present a new way to mitigate focal-ratio degradation (FRD) when using optical fibres to transport multimode light. Our approach exploits a custom multicore fibre (MCF) with six dissimilar cores that are single-mode at ∼1550 nm wavelength and minimally coupled over 7 m. We fabricated adiabatic mode-selective photonic lanterns (PLs) at each end of the MCF to create a fibre link with multimode ports, the PLs coupling each spatial mode of the multimode ports to a specific core of the MCF and vice versa. The PL-MCF-PL link exhibits superior FRD behaviour compared to a conventional multimode fibre that also supports six modes, because it inhibits the transfer of light from lower order modes to higher order modes. These results open up a potential powerful new approach to mitigate FRD in multimode fibre links, with particular applications in astronomical instruments.
| Original language | English |
|---|---|
| Pages (from-to) | 2381-2388 |
| Number of pages | 8 |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 502 |
| Issue number | 2 |
| Early online date | 30 Jan 2021 |
| DOIs | |
| Publication status | Published - 1 Apr 2021 |
Bibliographical note
Publisher Copyright:© 2021 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society.
Data Availability Statement
Raw data will be made available on the Heriot-Watt University PURE system (Available at https://doi.org/10.17861/affbdaf5-96d2-4f31-9fcd-5910021049e4).Funding
This work was funded by the UK STFC through grants ST/N000544/1 and ST/N000625/1, and by the European Union Horizon 2020 grant 730890 (OPTICON).
Keywords
- instrumentation: miscellaneous
- instrumentation: spectrograph
- methods: data analysis
- techniques: miscellaneous
- techniques: spectroscopic
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science