Projects in progress

Publication list with hyperlink 

As of 2022 July 31st the project gathers:

17 conference publications and 8 refereed publications, as well as 2 defended PhD thesis. 

• Project overview publications

• The segmented pupil experiment for exoplanet detection VI. From early design to first lights

      Martinez et al. Proceeding of the SPIE 2022

• The segmented pupil experiment for exoplanet detection V. System control and software infrastructure 

      Martinez et al. Proceeding of the SPIE 2022

• The segmented pupil experiment for exoplanet detection. IV. A versatile image-based wavefront sensor for active optics 

      Martinez et al. Proceeding of the SPIE 2020

• The segmented pupil experiment for exoplanet detection. III. Advances and first light with segment cophasing 

      Martinez et al. Proceeding of the SPIE 2018

• The segmented pupil experiment for exoplanet detection. II. Design advances and progress overview

     Martinez et al. Proceeding of the SPIE 2016

• The segmented pupil experiment for exoplanet detection

      Martinez et al. Proceeding of the SPIE 2014

• The segmented pupil experiment for exoplanet detection: SPEEDing up R&D towards high-contrast imaging instruments for the E-ELT

      Martinez et al. ESO Messenger 2015 n°159

• Experimental results obtained on the SPEED testbed
  

• Key hardware studies publications

• Gearing up the SPEED wavefront shaping strategy 

      Doyen et al. Proceeding of the SPIE 2020

• A metrological characterization of the SPEED test-bed PIAACMC components  

      Barjot et al. Proceeding of the SPIE 2020

• High-contrast at small angular separations: II. Impact on the dark hole of a realistic optical setup with two deformable mirrors

     Beaulieu et al. MNRAS 2020, 498

• Design and manufacturing of a multi-zone phase-shifting coronagraph mask for extremely large telescopes

     Martinez et al. A&A 2020, Vol. 635, A126

• Fast-modulation imaging with the self-coherent camera

     Martinez, A&A Letter 2019, 629, L10

• An end-to-end Fresnel propagation model for SPEED : PIAACMC implementation and performance

     Beaulieu et al. Proceeding of the SPIE 2018

• Design, specification and manufacturing of a PIAACMC for the SPEED testbed

     Martinez et al. Proceeding of the SPIE 2018

• Fine cophasing of segmented aperture telescopes with ZELDA, a Zernike wavefront sensor in the diffraction-limited regime

     Janin-Potiron et al. A&A 2017

• High-contrast imaging at small separations : impact of the optical configuration of two deformable mirrors on dark holes

     Beaulieu et al. MNRAS 2017, 469

• Self-coherent camera as a focal plane phasing sensor

     Janin-Potiron et al. A&A 2016, 592, A110

• The self-coherent camera as phasing sensor : from numerical simulations to early experiments

     Janin-Potiron et al. Proceeding of the SPIE 2016

• SPEED design optimization via Fresnel propagation analysis

      Beaulieu et al. Proceeding of the SPIE 2016

• The self-coherent camera as a focal plane phasing sensor

     Janin-Potiron et al. EAS publications series 78-79 2016

• System analysis of the segmented pupil experiment for exoplanet detection – SPEED – in view of the ELTs

     Preis et al. Proceeding of the AO4ELT 4th Edition 2015

• A Fresnel propagation analysis for SPEED    

     Beaulieu et al. Proceeding of the AO4ELT 4th Edition 2015

• The self-coherent camera as a phasing sensor : overview and early comparison with the Zenike phase contrast sensor

     Janin-Potiron et al. Proceeding of the AO4ELT 4th Edition 2015

• Project related publications 
  

• Analytical decomposition of Zernike and hexagonal modes over an hexagonal segmented optical aperture

     Janin-Potiron, Martinez and Carbillet, OSA Continuum  2018 - 1(2), 715-726 

• Laser guide stars used for cophasing broad capture ranges

      Martinez and Janin-Potiron, A&A Letter 2016, 593, L1

• Thesis 
  

• Correction active des discontinuités pupillaires des télescopes à miroir segmenté pour l’imagerie haut contraste et la haute résolution angulaire

     Janin-Potiron Pierre, Université Côte d’Azur 2017 (Prix SF2A 2018)

• Imagerie optique à très haut contraste : une approche instrumentale optimale

      Beaulieu Mathilde, Université Côte d’Azur 2017

The architectural principle of the SPEED bench is presented in the above diagram. The field of view of interest is restricted to 8 λ/D in radius given the aimed objective of high contrast at small angular separations. The bench is therefore composed of a visible cophasing optical path (in blue) and a near-infrared path (in red) dedicated to high contrast. 

The common path is in orange colour in the 3D CAO view of the bench presented above. The visible path dedicated to the optical cophasing corresponds to the blue lines and the near-infrared path, dedicated to high-contrast imaging, corresponds to the red lines.

The Speed bench is installed in a clean-room environment (ISO7 classroom) at the Lagrange Laboratory, FIZEAU building on the Valrose campus in the city centre of Nice.

The SPEED project is an instrumental facility to study high-contrast imaging techniques with a segmented telescope struggled to very close angular separations in view of the next generation of ground- and space-based observatories. The bench combines a segmented telescope simulator with 163 segments, co-phasing optics (in the optical domain), and multi-DM architecture combined with deep coronagraphic imaging (in the near-infrared). The scientific field of view is from 1 to 8 λ/D in the H-band. In terms of key hardware, the bench combines a super-continuum NKT light source, an integral sphere, a tip/tilt mirror, an IRIS AO PTT489 segmented deformable mirror, 2 Kilo-C deformable mirrors from Boston Micromachines, an SCC-PS and/or ZELDA-PS (cophasing sensors), a PIAACMC (coronagraph), and an SCC. The bench is currently under the AIT phase in an ISO 7 room in the FIZEAU building. The SPEED project benefits from wide local, national, and European support (see at the bottom of the page).

In particular, the SPEED testbed searches for participating in the future instrumental development of an exoplanet hunter around late-type stars (M-stars). 

Three main research axes are studied: 

• cophasing optics (fine cophasing and monitoring) from the scientific image 
• very small IWA coronagraphy (inner working angle)
• active optics with multi-DM for high-contrast imaging (wavefront shaping for dark hole generation)

The testbed will also offer the possibility to study ELT's inherent drawbacks from its segmented nature and emphasize the study of their impact on high-contrast (e.g., missing segment, cophasing residual, mixing XAO residuals and cophasing residuals, etc.)

All the SPEED OAPs have been realized by the OCA optical workshop (D. Vernet).

Crédit: J. Dejonghe - C. Gouvret

 Simulated pupil of the  SPEED telescope simulator exhibiting 30% central obscuration, 6 spiders and 163 segments. 

Simulated NiR PSF image. The Blue circle defines the wavefront shaping DMs cut-off frequency. The red circle defines the field of view (FoV) targetted by the project and is restricted to small angular separations. Green circles localized the first diffractive signatures from the primary mirror segmentation.