Vortex Optical Demonstrator for Coronagraphic Applications

Testbed name Managing institution
VODCA Space science, Technologies, and Astrophysics Research (STAR) Institute, University of Liège
Contact person People willing to give talks
Olivier Absil
  • Olivier Absil
  • Gilles Orban de Xivry
  • Christian Delacroix
    		•
    Main scientific focus Testbed environment
    The prime purpose of VODCA is to test and validate manufactured infrared vortex phase masks (and in particular Annular Groove Phase Masks) at the appropriate wavelengths: near- to mid- infrared corresponding to the H, K, L and M bands (1.5 to 4.6 um). VODCA is located in a ISO 7 clean room (class 10000). The optical bench sits on an active vibration isolation system.
    Key hardware items Current status
  • supercontinuum laser source delivering single-mode broadband beam from approx. 1.5 to 4 um.
  • infrared InSb camera from FLIR, cooled to 77K and operating in the 1.5-5.5um wavelength range
  • ALPAO deformable mirror with 97 actuators
  • QCL laser producing a single-mode narrow-line emission at around 4.6 um
    		•

    In operation. The bench allows to reach the intrinsic on-axis rejection limit of the manufactured Annular Groove Phase Masks (up to a few 1000:1 in broad L-band).

    Future of the bench: 1) testing of newly manufactured AGPM, 2) new apodization and wavefront sensing techniques, 3) charge 4 and beyond vortices testing.
    Software, languages Is our software shared?
  • Python
  • Labview
    		•  Not currently but could be if useful.

    Reference papers:
  • The VORTEX coronagraphic test bench, Jolivet et al. 2014
  • Three years of harvest with the vector vortex coronagraph in the thermal infrared, Absil et al. 2016
  • Post-coronagraphic PSF sharpening with the vortex coronagraph, Orban de Xivry et al. 2017
  • L- and M-band annular groove phase mask in lab performance assessment on the vortex optical demonstrator for coronagraphic applications, Jolivet et al. 2019