Demonstration of an efficient, photonic-based astronomical spectrograph on an 8-m telescope.
Opt Express
; 25(15): 17753-17766, 2017 Jul 24.
Article
em En
| MEDLINE
| ID: mdl-28789267
ABSTRACT
We demonstrate for the first time an efficient, photonic-based astronomical spectrograph on the 8-m Subaru Telescope. An extreme adaptive optics system is combined with pupil apodiziation optics to efficiently inject light directly into a single-mode fiber, which feeds a compact cross-dispersed spectrograph based on array waveguide grating technology. The instrument currently offers a throughput of 5% from sky-to-detector which we outline could easily be upgraded to â¼ 13% (assuming a coupling efficiency of 50%). The isolated spectrograph throughput from the single-mode fiber to detector was 42% at 1550 nm. The coupling efficiency into the single-mode fiber was limited by the achievable Strehl ratio on a given night. A coupling efficiency of 47% has been achieved with â¼ 60% Strehl ratio on-sky to date. Improvements to the adaptive optics system will enable 90% Strehl ratio and a coupling of up to 67% eventually. This work demonstrates that the unique combination of advanced technologies enables the realization of a compact and highly efficient spectrograph, setting a precedent for future instrument design on very-large and extremely-large telescopes.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
Opt Express
Assunto da revista:
OFTALMOLOGIA
Ano de publicação:
2017
Tipo de documento:
Article