VPHGs for WEAVE: design, manufacturing and characterization - Observatoire de Paris Access content directly
Conference Papers Year : 2018

VPHGs for WEAVE: design, manufacturing and characterization

Andrea Bianco
  • Function : Author
Giorgio Pariani
  • Function : Author
Matteo Aliverti
  • Function : Author
Alessio Zanutta
  • Function : Author
James Arns
  • Function : Author
Johan Pragt
  • Function : Author
Remko Stuik
  • Function : Author
Kevin Middleton
  • Function : Author
Ian Tosh
  • Function : Author
Gavin Dalton
  • Function : Author
Scott Trager
  • Function : Author
Don Carlos Abrams
  • Function : Author
Jose Alfonso Lopez Aguerri
  • Function : Author
Antonella Vallenari
  • Function : Author
Esperanza Carrasco
  • Function : Author

Abstract

WEAVE is the next-generation optical spectroscopy facility for the William Herschel Telescope (WHT). It shows two channels (blue and red) and two working modes, a low-resolution (R=3,000-7,500) and a high-resolution (R=13,000- 25,000). The dispersing elements of the spectrograph are Volume Phase Holographic Gratings (VPHGs), two for the lower resolution mode and three for the higher resolution mode. Such gratings have a large size (clear aperture > 190 mm) and they are characterized by some key features, i.e. diffraction efficiency, wavefront error and dispersion that affect the final performances of the spectrograph. The VPHGs have been produced by KOSI based on the WEAVE design. After that, the VPHGs have been characterized, showing interesting results in terms of diffraction efficiency that reached peak values of 90%. As for the wavefront distortion, which is one of the critical aspect in VPHG technology, a different behavior between medium and high resolution elements was found. A larger wavefront distortion have been measured in the high resolution elements, because of the higher aspect ratio. A polishing process on the assembled VPHGs has been performed in order to reduce the wavefront distortion. Here, the results are presented and the specific issues discussed.
No file

Dates and versions

obspm-04072882 , version 1 (18-04-2023)

Identifiers

Cite

Andrea Bianco, Giorgio Pariani, Matteo Aliverti, Alessio Zanutta, James Arns, et al.. VPHGs for WEAVE: design, manufacturing and characterization. Proceedings of the SPIE, 0000, à renseigner, Unknown Region. ⟨10.1117/12.2311693⟩. ⟨obspm-04072882⟩
2 View
0 Download

Altmetric

Share

Gmail Facebook X LinkedIn More