XAO-assisted coronagraphy with SHARK NIR: from simulations to laboratory tests. (arXiv:2011.12899v1 [astro-ph.IM])

XAO-assisted coronagraphy with SHARK NIR: from simulations to laboratory tests. (arXiv:2011.12899v1 [astro-ph.IM])
<a href="http://arxiv.org/find/astro-ph/1/au:+Umbriaco_G/0/1/0/all/0/1">Gabriele Umbriaco</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carolo_E/0/1/0/all/0/1">Elena Carolo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vassallo_D/0/1/0/all/0/1">Daniele Vassallo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Farinato_J/0/1/0/all/0/1">Jacopo Farinato</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baudoz_P/0/1/0/all/0/1">Pierre Baudoz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carlotti_A/0/1/0/all/0/1">Alexis Carlotti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Greggio_D/0/1/0/all/0/1">Davide Greggio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marafatto_L/0/1/0/all/0/1">Luca Marafatto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bergomi_M/0/1/0/all/0/1">Maria Bergomi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Viotto_V/0/1/0/all/0/1">Valentina Viotto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Agapito_G/0/1/0/all/0/1">Guido Agapito</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Biondi_F/0/1/0/all/0/1">Federico Biondi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chinellato_S/0/1/0/all/0/1">Simonetta Chinellato</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pascale_M/0/1/0/all/0/1">Marco De Pascale</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dima_M/0/1/0/all/0/1">Marco Dima</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DOrazi_V/0/1/0/all/0/1">Valentina D&#x27;Orazi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Esposito_S/0/1/0/all/0/1">Simone Esposito</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Magrin_D/0/1/0/all/0/1">Demetrio Magrin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mesa_D/0/1/0/all/0/1">Dino Mesa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pedichini_F/0/1/0/all/0/1">Fernando Pedichini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pinna_E/0/1/0/all/0/1">Enrico Pinna</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Portaluri_E/0/1/0/all/0/1">Elisa Portaluri</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Puglisi_A/0/1/0/all/0/1">Alfio Puglisi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ragazzoni_R/0/1/0/all/0/1">Roberto Ragazzoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stangalini_M/0/1/0/all/0/1">Marco Stangalini</a>

Several Extreme Adaptive Optics (XAO) systems dedicated to the detection and
characterisation of the exoplanets are currently in operation for 8-10 meter
class telescopes. Coronagraphs are commonly used in these facilities to reject
the diffracted light of an observed star and enable direct imaging and
spectroscopy of its circumstellar environment. SHARK-NIR is a coronagraphic
camera that will be implemented at the Large Binocular Telescope (LBT). After
an extensive simulation campaign, SHARK-NIR team selected a suite of
coronagraphic techniques to be implemented in the instrument in order to fulfil
the scientific requirements. In summary, the Gaussian Lyot coronagraph is the
option to serve all those science cases requiring field-stabilization and
moderate contrast. Observations in pupil-stabilized mode to search for
exoplanets can take advantage of three Shaped Pupil masks (SPC) and a
Four-Quadrant Phase Mask (FQPM) coronagraph. The SPC are designed for high
contrast on a small field close to the star and are robust to image and pupil
jitter. The FQPM allows to access the entire scientific FoV (18”x18”) and
delivers excellent performance in ideal conditions (high Strehl ratios), but
performance is still good, both close and further away from the star, even at
lower Strehl and with moderate vibrations. After the procurement phase, the
coronagraphic masks were delivered to our labs and we started to test their
performance on the optical bench and define the alignment procedures that will
be employed in the final integration of the instrument in our cleaning room. In
this article, we describe the tests that we performed in the lab with SHARK-NIR
coronagraphs. We measured the contrast achievable with each technique in
very-high Strehl conditions and defined the alignment-integration procedures.

Several Extreme Adaptive Optics (XAO) systems dedicated to the detection and
characterisation of the exoplanets are currently in operation for 8-10 meter
class telescopes. Coronagraphs are commonly used in these facilities to reject
the diffracted light of an observed star and enable direct imaging and
spectroscopy of its circumstellar environment. SHARK-NIR is a coronagraphic
camera that will be implemented at the Large Binocular Telescope (LBT). After
an extensive simulation campaign, SHARK-NIR team selected a suite of
coronagraphic techniques to be implemented in the instrument in order to fulfil
the scientific requirements. In summary, the Gaussian Lyot coronagraph is the
option to serve all those science cases requiring field-stabilization and
moderate contrast. Observations in pupil-stabilized mode to search for
exoplanets can take advantage of three Shaped Pupil masks (SPC) and a
Four-Quadrant Phase Mask (FQPM) coronagraph. The SPC are designed for high
contrast on a small field close to the star and are robust to image and pupil
jitter. The FQPM allows to access the entire scientific FoV (18”x18”) and
delivers excellent performance in ideal conditions (high Strehl ratios), but
performance is still good, both close and further away from the star, even at
lower Strehl and with moderate vibrations. After the procurement phase, the
coronagraphic masks were delivered to our labs and we started to test their
performance on the optical bench and define the alignment procedures that will
be employed in the final integration of the instrument in our cleaning room. In
this article, we describe the tests that we performed in the lab with SHARK-NIR
coronagraphs. We measured the contrast achievable with each technique in
very-high Strehl conditions and defined the alignment-integration procedures.

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