Wavefront control for minimization of speckle coupling into a fiber injection unit based on the electric field conjugation algorithm
| Autor: | Nemanja Jovanovic, Garreth Ruane, Nikita Klimovich, Dimitri Mawet, Jacques-Robert Delorme, Yeyuan Xin, Jorge Llop Sayson, Daniel Echeverri |
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| Přispěvatelé: | Close, Laird M., Schreiber, Laura, Schmidt, Dirk |
| Rok vydání: | 2018 |
| Předmět: |
Physics
Wavefront business.industry Astrophysics::Instrumentation and Methods for Astrophysics Single-mode optical fiber 01 natural sciences Deformable mirror law.invention Starlight 010309 optics Speckle pattern Cardinal point Optics law 0103 physical sciences Astrophysics::Earth and Planetary Astrophysics business 010303 astronomy & astrophysics Coronagraph Spectrograph |
| Zdroj: | Adaptive Optics Systems VI. |
| DOI: | 10.1117/12.2313657 |
| Popis: | A fiber injection unit situated in the focal plane behind a coronagraph feeding a high resolution spectrograph can be used to couple light from an exoplanet to obtain high resolution spectra with improved sensitivity. However, the signal-to-noise ratio of the planet signal is limited by the coupling of starlight into the single mode fiber. To minimize this coupling, we need to apply a control loop on the stellar wavefront at the input of the fiber. We present here a wavefront control algorithm based on the formalism of the Electric Field Conjugation (EFC) controller that accounts for the effect of the fiber. The control output is the overlap integral of the electric field with the fundamental mode of a single mode fiber. This overlap integral is estimated by sending probes to a deformable mirror. We present results from simulations, and laboratory results obtained at the Caltech Exoplanet Technology Lab’s transmissive testbed. We show that our approach offers a significant improvement in starlight suppression through the fiber relative to a conventional EFC controller. This new approach improves the contrast of a high contrast instrument and could be used in future missions. |
| Databáze: | OpenAIRE |
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