Prime Focus Spectrograph for the Subaru telescope: Massively multiplexed optical and near-infrared fiber spectrograph

Hajime Sugai, Naoyuki Tamura, Hiroshi Karoji, Atsushi Shimono, Naruhisa Takato, Masahiko Kimura, Youichi Ohyama, Akitoshi Ueda, Hrand Aghazarian, Marcio Vital De Arruda, Robert H. Barkhouser, Charles L. Bennett, Steve Bickerton, Alexandre Bozier, David F. Braun, Khanh Bui, Christopher M. Capocasale, Michael A. Carr, Bruno Castilho, Yin Chang ChangHsin Yo Chen, Richard C.Y. Chou, Olivia R. Dawson, Richard G. Dekany, Eric M. Ek, Richard S. Ellis, Robin J. English, Didier Ferrand, Décio Ferreira, Charles D. Fisher, Mirek Golebiowski, James E. Gunn, Murdock Hart, Timothy M. Heckman, Paul T.P. Ho, Stephen Hope, Larry E. Hovland, Shu Fu Hsu, Yen Shan Hu, Pin Jie Huang, Marc Jaquet, Jennifer E. Karr, Jason G. Kempenaar, Matthew E. King, Olivier Le Fèvre, David Le Mignant, Hung Hsu Ling, Craig Loomis, Robert H. Lupton, Fabrice Madec, Peter Mao, Lucas Souza Marrara, Brice Ménard, Chaz Morantz, Hitoshi Murayama, Graham J. Murray, Antonio Cesar De Oliveira, Claudia Mendes De Oliveira, Ligia Souza De Oliveira, Joe D. Orndorff, Rodrigo De Paiva Vilaça, Eamon J. Partos, Sandrine Pascal, Thomas Pegot-Ogier, Daniel J. Reiley, Reed Riddle, Leandro Santos, Jesulino Bispo Dos Santos, Mark A. Schwochert, Michael D. Seiffert, Stephen A. Smee, Roger M. Smith, Ronald E. Steinkraus, Laerte Sodré, David N. Spergel, Christian Surace, Laurence Tresse, Clément Vidal, Sebastien Vives, Shiang Yu Wang, Chih Yi Wen, Amy C. Wu, Rosie Wyse, Chi Hung Yan

Research output: Contribution to journalArticlepeer-review

47 Scopus citations


The Prime Focus Spectrograph (PFS) is an optical/near-infrared multifiber spectrograph with 2394 science fibers distributed across a 1.3-deg diameter field of view at the Subaru 8.2-m telescope. The wide wavelength coverage from 0.38 μm to 1.26 μm, with a resolving power of 3000, simultaneously strengthens its ability to target three main survey programs: cosmology, galactic archaeology and galaxy/AGN evolution. A medium resolution mode with a resolving power of 5000 for 0.71 μm to 0.89 μm will also be available by simply exchanging dispersers. We highlight some of the technological aspects of the design. To transform the telescope focal ratio, a broad-band coated microlens is glued to each fiber tip. A higher transmission fiber is selected for the longest part of the cable system, optimizing overall throughput; a fiber with low focal ratio degradation is selected for the fiber-positioner and fiber-slit components, minimizing the effects of fiber movements and fiber bending. Fiber positioning will be performed by a positioner consisting of two stages of piezo-electric rotary motors. The positions of these motors are measured by taking an image of artificially back-illuminated fibers with the metrology camera located in the Cassegrain container; the fibers are placed in the proper location by iteratively measuring and then adjusting the positions of the motors. Target light reaches one of the four identical fast-Schmidt spectrograph modules, each with three arms. The PFS project has passed several project-wide design reviews and is now in the construction phase.

Original languageEnglish (US)
Article number035001
JournalJournal of Astronomical Telescopes, Instruments, and Systems
Issue number3
StatePublished - Jul 1 2015

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Control and Systems Engineering
  • Instrumentation
  • Astronomy and Astrophysics
  • Mechanical Engineering
  • Space and Planetary Science


  • astronomy
  • fiber applications
  • infrared systems
  • optical systems
  • spectrographs


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