Astrophotonics: The application of photonic technology to astronomy

S. C. Ellis*, S. Kuhlmann, K. Kuehn, H. Spinka, D. Underwood, R. R. Gupta, L. Ocola, P. Liu, G. Wei, N. P. Stern, J. Bland-Hawthorn, P. Tuthill

*Corresponding author for this work

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

3 Scopus citations


Integrated optics has the potential to play a transformative role in astronomical instrumentation. It has already made a significant impact in the field of optical interferometry, through the use of planar waveguide arrays for beam combination and phase-shifting. Additionally, the potential benefits of micro-spectrographs based on array waveguide gratings have also been demonstrated. Here we examine a new application of integrated optics, using ring resonators as notch filters to remove the signal from atmospheric OH emission lines from astronomical spectra. We also briefly discuss their use as frequency combs for wavelength calibration and as drop filters for Doppler planet searches. We discuss the theoretical requirements for ring resonators for OH suppression. We find that small radius (< 10 μm), high index contrast (Si or Si3N4) rings are necessary to provide an adequate free spectral range. The suppression depth, resolving power, and throughput for efficient OH suppression can be realised with critically coupled rings with high self-coupling coefficients. We report on preliminary laboratory tests of our Si and Si3N4 rings and give details of their fabrication. We demonstrate high self-coupling coefficients (> 0:9) and good control over the free spectral range and wavelength separation of multi-ring devices. Current devices have Q 4000 and 10 dB suppression, which should be improved through further optimisation of the coupling coefficients. The overall prospects for the use of ring resonators in astronomical instruments is promising, provided efficient fibre-chip coupling can be achieved.

Original languageEnglish (US)
Title of host publicationIntegrated Optics
Subtitle of host publicationPhysics and Simulations III
EditorsJiri Ctyroky, Inigo Molina-Fernandez, Pavel Cheben
ISBN (Electronic)9781510609853
StatePublished - 2017
EventIntegrated Optics: Physics and Simulations III 2017 - Prague, Czech Republic
Duration: Apr 24 2017Apr 25 2017

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherIntegrated Optics: Physics and Simulations III 2017
Country/TerritoryCzech Republic


  • Astronomical optics
  • Filters
  • Micro-optical devices
  • Ring Resonators
  • Waveguides

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Astrophotonics: The application of photonic technology to astronomy'. Together they form a unique fingerprint.

Cite this