Speciality optical fibres for astronomy

S. C. Ellis*, J. Bland-Hawthorn

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contribution

4 Citations (Scopus)

Abstract

Astrophotonics is a rapidly developing area of research which applies photonic technology to astronomical instrumentation. Such technology has the capability of significantly improving the sensitivity, calibration and stability of astronomical instruments, or indeed providing novel capabilities which are not poßible using claßical optics. We review the development and application of speciality fibres for astronomy, including multi-mode to single-mode converters, notch filters and frequency combs. In particular we focus on our development of instruments designed to filter atmospheric emißion lines to enable much deeper spectroscopic observations in the near-infrared. These instruments employ two novel photonic technologies. First, we have developed complex aperiodic fibre Bragg gratings which filter over 100 irregularly spaced wavelengths in a single device, covering a bandwidth of over 200 nm. However, astronomical instruments require highly multi-mode fibres to enable sufficient coupling into the fibre, since atmospheric turbulence heavily distorts the wavefront. But photonic technologies such as fibre Bragg gratings, require single mode fibres. This problem is solved by the photonic lantern, which enables efficient coupling from a multi-mode fibre to an array of single-mode fibres and vice versa. We present the results of laboratory tests of these technologies and of on-sky experiments made using the first instruments to deploy these technologies on a telescope. These tests show that the fibre Bragg gratings suppreß the night sky background by a factor of 9. Current instruments are limited by thermal and detector emißion. Planned instruments should improved the background suppreßion even further, by optimising the design of the spectrograph for the properties of the photonic components. Finally we review ongoing research in astrophotonics, including multi-moded multicore fibre Bragg gratings, which enable multiple gratings to be written into the same device simultaneously, femtosecond direct-write photonic lanterns and Bragg gratings, and complex notch filters and frequency combs using microring resonators, and plans for future astrophotonic instrumentation.

Original languageEnglish
Title of host publicationMicro-Structured and Specialty Optical Fibres IV
EditorsKyriacos Kalli, Jiri Kanka, Alexis Mendez
Place of PublicationBellingham, Washington
PublisherSPIE
Number of pages15
ISBN (Electronic)9781628416282
DOIs
Publication statusPublished - 7 May 2015
Externally publishedYes
EventMicro-Structured and Specialty Optical Fibres IV - Prague, Czech Republic
Duration: 15 Apr 201516 Apr 2015

Publication series

NameProceedings of SPIE
Volume9507
ISSN (Print)0277-786X

Conference

ConferenceMicro-Structured and Specialty Optical Fibres IV
CountryCzech Republic
CityPrague
Period15/04/1516/04/15

Keywords

  • Astrophysics
  • Fibre Bragg gratings
  • Fibres
  • Photonic lanterns

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  • Cite this

    Ellis, S. C., & Bland-Hawthorn, J. (2015). Speciality optical fibres for astronomy. In K. Kalli, J. Kanka, & A. Mendez (Eds.), Micro-Structured and Specialty Optical Fibres IV [95070C] (Proceedings of SPIE; Vol. 9507). Bellingham, Washington: SPIE. https://doi.org/10.1117/12.2178427