PRAXIS: a low background NIR spectrograph for fibre Bragg grating OH suppression

Anthony Horton, Simon Ellis, Jon Lawrence, Joss Bland-Hawthorn

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionResearchpeer-review

Abstract

Fibre Bragg grating (FBG) OH suppression is capable of greatly reducing the bright sky background seen by near infrared spectrographs. By filtering out the airglow emission lines at high resolution before the light enters the spectrograph this technique prevents scattering from the emission lines into interline regions, thereby reducing the background at all wavelengths. In order to take full advantage of this sky background reduction the spectrograph must have very low instrumental backgrounds so that it remains sky noise limited. Both simulations and real world experience with the prototype GNOSIS system show that existing spectrographs, designed for higher sky background levels, will be unable to fully exploit the sky background reduction. We therefore propose PRAXIS, a spectrograph optimised specifically for this purpose. 

The PRAXIS concept is a fibre fed, fully cryogenic, fixed format spectrograph for the J and H-bands. Dark current will be minimised by using the best of the latest generation of NIR detectors while thermal backgrounds will be reduced by the use of a cryogenic fibre slit. Optimised spectral formats and the use of high throughput volume phase holographic gratings will further enhance sensitivity. Our proposal is for a modular system, incorporating exchangeable fore-optics units, integral field units and OH suppression units, to allow PRAXIS to operate as a visitor instrument on any large telescope and enable new developments in FBG OH suppression to be incorporated as they become available. As a high performance fibre fed spectrograph PRAXIS could also serve as a testbed for other astrophotonic technologies.

LanguageEnglish
Title of host publicationModern Technologies in Space- and Ground-Based Telescopes and Instrumentation II
EditorsRamón Navarro, Colin R. Cunningham, Eric Prieto
Place of PublicationBellingham, WA
PublisherSPIE
Pages84501V-1-84501V-6
Number of pages6
Volume8450
ISBN (Print)9780819491510
DOIs
Publication statusPublished - 2012
Externally publishedYes
EventModern Technologies in Space- and Ground-Based Telescopes and Instrumentation II - Amsterdam, Netherlands
Duration: 1 Jul 20126 Jul 2012

Other

OtherModern Technologies in Space- and Ground-Based Telescopes and Instrumentation II
CountryNetherlands
CityAmsterdam
Period1/07/126/07/12

Fingerprint

Spectrographs
Spectrograph
Fiber Grating
Fiber Bragg gratings
Bragg Grating
Bragg gratings
spectrographs
retarding
sky
fibers
Cryogenics
Fiber
Fibers
Infrared spectrographs
cryogenics
format
Holographic gratings
Integral Field Unit
Dark currents
Holographic Grating

Keywords

  • Fibre Bragg grating
  • Infrared
  • OH suppression
  • Spectroscopy

Cite this

Horton, A., Ellis, S., Lawrence, J., & Bland-Hawthorn, J. (2012). PRAXIS: a low background NIR spectrograph for fibre Bragg grating OH suppression. In R. Navarro, C. R. Cunningham, & E. Prieto (Eds.), Modern Technologies in Space- and Ground-Based Telescopes and Instrumentation II (Vol. 8450, pp. 84501V-1-84501V-6). [84501V] Bellingham, WA: SPIE. https://doi.org/10.1117/12.924874
Horton, Anthony ; Ellis, Simon ; Lawrence, Jon ; Bland-Hawthorn, Joss. / PRAXIS : a low background NIR spectrograph for fibre Bragg grating OH suppression. Modern Technologies in Space- and Ground-Based Telescopes and Instrumentation II. editor / Ramón Navarro ; Colin R. Cunningham ; Eric Prieto. Vol. 8450 Bellingham, WA : SPIE, 2012. pp. 84501V-1-84501V-6
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title = "PRAXIS: a low background NIR spectrograph for fibre Bragg grating OH suppression",
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Horton, A, Ellis, S, Lawrence, J & Bland-Hawthorn, J 2012, PRAXIS: a low background NIR spectrograph for fibre Bragg grating OH suppression. in R Navarro, CR Cunningham & E Prieto (eds), Modern Technologies in Space- and Ground-Based Telescopes and Instrumentation II. vol. 8450, 84501V, SPIE, Bellingham, WA, pp. 84501V-1-84501V-6, Modern Technologies in Space- and Ground-Based Telescopes and Instrumentation II, Amsterdam, Netherlands, 1/07/12. https://doi.org/10.1117/12.924874

PRAXIS : a low background NIR spectrograph for fibre Bragg grating OH suppression. / Horton, Anthony; Ellis, Simon; Lawrence, Jon; Bland-Hawthorn, Joss.

Modern Technologies in Space- and Ground-Based Telescopes and Instrumentation II. ed. / Ramón Navarro; Colin R. Cunningham; Eric Prieto. Vol. 8450 Bellingham, WA : SPIE, 2012. p. 84501V-1-84501V-6 84501V.

Research output: Chapter in Book/Report/Conference proceedingConference proceeding contributionResearchpeer-review

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Horton A, Ellis S, Lawrence J, Bland-Hawthorn J. PRAXIS: a low background NIR spectrograph for fibre Bragg grating OH suppression. In Navarro R, Cunningham CR, Prieto E, editors, Modern Technologies in Space- and Ground-Based Telescopes and Instrumentation II. Vol. 8450. Bellingham, WA: SPIE. 2012. p. 84501V-1-84501V-6. 84501V https://doi.org/10.1117/12.924874