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SPIRou / Infrared SpectroPolarimeter

2016 March: Integration of the SPIRou Cassegrain module at IRAP/OMP

The three sections of the SPIRou Cassegrain module are being assembled and tested at IRAP/OMP

Spectrograph optical bench

Integration of the lower sections
of the Cassegrain module,
including the tip-tilt / guiding
and the polarimetric units,
in the P2IS clean room at IRAP / OMP

The SPIRou Cassegrain module is currently being integrated and tested in the P2IS clean room at IRAP / OMP.  This module splits into three separate sections: 

  • the upper section interfacing SPIRou with the telescope and containing some calibration devices, 
  • the middle section, correcting for atmospheric dispersion and including tip-tilt / guiding facilities thanks to which the image of the star to be observed is stabilized with respect to the instrument entrance aperture (by correcting for the image motions caused by atmospheric turbulence and telescope instabilities), 
  • the lower section consisting of a polarimetric unit, performing an achromatic polarimetric analysis of the incoming stellar light and splitting the main beam into 2 orthogonally polarized beams to be injected in fluoride fibers that convey the light to the SPIRou cryogenic spectrograph.  

The Cassegrain module, whose electromechanical behavior is currently being tested down to temperatures of -10° in the dedicated climatic chamber of the IRAP / OMP clean room, will soon integrate all optical components that have already been (or are about to be) delivered to IRAP - in particular the atmospheric dispersion corrector, the Image Stabilization Unit, the viewing / guiding nIR Raptor camera, the input / output focal reducers, the Wollaston prism, and a pair of super-achromatic Fresnel rhombs.  

Upper section of the Cassegrain module

Integration of the upper section of the Cassegain module, interfacing SPIRou with the telescope and including calibration devices

ISU

Image Stabilization Unit of the SPIRou Cassegrain module, correcting for image motions caused by atmospheric turbulence and telescope instabilities

ISU Tests

Lab tests of the Image Stabilization Unit in the P2IS clean room of IRAP / OMP, with the climatic chamber in the back (right side)