NIRPS Front End

The NIRPS front end (NFE) is a subsystem of the NIRPS instrument. It is directly attached at the back of the ESO 3.6m telescope rotator in La Silla. Its main goals are to collect the starlight, separate the visible and the near-infrared light and distribute the visible light to the HARPS Cassegrain Fiber Adapter (HCFA) or bonnette and the NIR light (YJH-band) to the NIRPS fibers. The existing HCFA is kept as is and its position wrt to the telescope remains the same. However the bracket, on which the HCFA is mounted, is completely new. Indeed, the new structure supports both the HARPS front-end and NIRPS front-end components.

The NFE support structure consists of :

  •  NIRPS Cassegrain adapter: This part is mounted on the 3.6 telescope rotator interface. Moreover, it is the optical bench on which most of the NIRPS optical components are mounted.
  • HARPS Front-end bracket : this part is holding the existing HCFA, the NIRPS/HARPS dichroic, the HARPS guiding camera and the associated optical components.
  • Monopod : 3 monopods are holding the HARPS Front-end bracket. They are mounted onto the NIRPS Cassegrain adapter.

The optical components, cameras and mechanisms constituting the NFE are listed hereafter:

  • HARPS/NIRPS dichroic mechanism
  • Science/WFS dichroic
  • ADC
  • Deformable mirror (DM) mounted on a tip-tilt mechanism
  • Wavefront sensor
  • NIR guiding camera
  • Visible guiding camera (TCCD in ESO language)
  • Fiber heads mechanism
  • Fold mirrors
  • Lenses
  • Calibration sources heads

The location of the various components is shown on the figures below. 

NIRPS optical design layout