Mid-infrared transmission gratings in chalcogenide glass manufactured using ultrafast laser inscription

David Lee, David Guillaume MacLachlan, Helen L. Butcher, Richard A. Brownsword, Damien Weidmann, Colin R Cunningham, Hermine Schnetler, Robert R Thomson

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

Abstract

Ultrafast laser inscription is a versatile manufacturing technique which can be used to modify the refractive index of various glasses on a microscopic scale. This enables the production of a number of photonic devices such as waveguides, beam-splitters, photonic lanterns, and diffraction gratings. In this paper, we report on the use of ultrafast laser inscription to fabricate volume phase transmission gratings in mid-infrared transmitting chalcogenide glass. We describe the optimisation of the laser inscription process parameters enhancing grating performances via the combination of spectrally resolved grating transmission measurements and theoretical analysis models. The first order diffraction efficiency of the gratings was measured at mid-infrared wavelengths (3-5 μm), and found to exceed 60% at the Littrow blaze wavelength, compared to a substrate external transmittance of 67%. This impressive result implies the diffraction efficiency should exceed 90% for a grating substrate treated with an anti-reflection coating. There is excellent agreement between the modelled grating efficiency and the measured data, and from a least squares fit to the measured data the refractive index modulation achieved during the inscription process is inferred. These encouraging initial results demonstrate that ultrafast laser inscription of chalcogenide glass may provide a potential new and alternative technology for the manufacture of astronomical diffraction gratings for use at near-infrared and mid-infrared wavelengths.

Original languageEnglish
Title of host publicationAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation II
PublisherSPIE
ISBN (Electronic)9781510602038
DOIs
Publication statusPublished - 22 Jul 2016
EventAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation II - Edinburgh, United Kingdom
Duration: 26 Jun 20161 Jul 2016

Publication series

NameProceedings of SPIE
PublisherSPIE
Volume9912
ISSN (Print)0277-786X

Conference

ConferenceAdvances in Optical and Mechanical Technologies for Telescopes and Instrumentation II
CountryUnited Kingdom
CityEdinburgh
Period26/06/161/07/16

Keywords

  • Chalcogenide Glass
  • Diffraction Grating
  • Mid-infrared
  • Ultrafast Laser Inscription

ASJC Scopus subject areas

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

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  • Cite this

    Lee, D., MacLachlan, D. G., Butcher, H. L., Brownsword, R. A., Weidmann, D., Cunningham, C. R., Schnetler, H., & Thomson, R. R. (2016). Mid-infrared transmission gratings in chalcogenide glass manufactured using ultrafast laser inscription. In Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation II [99122X] (Proceedings of SPIE; Vol. 9912). SPIE. https://doi.org/10.1117/12.2232531