Laser guide star AO project at the Subaru Telescope

Hideki Takami, Makoto Watanabe, Naruhisa Takato, Stephen Colley, Michael Eldred, Thomas Kane, Olivier Guyon, Masayuki Hattori, Miwa Goto, Masanori Iye, Yutaka Hayano, Yukiko Kamata, Nobuo Arimoto, Naoto Kobayashi, Yosuke Minowa

Research output: Contribution to journalConference articlepeer-review

19 Scopus citations


The laser guide star adaptive optics (AO) system for Subaru Telescope is presented. The system will be installed at the IR Nasmyth platform, whereas the current AO system with 36 elements is operating at the Cassegrain focus. The new AO system has a 188 element wavefront curvature sensor with photon counting APD modules which is the largest control element curvature sensor system ever. The system will have 4-10 W solid state sum-frequency laser to generate a laser guide star. The laser launching telescope with 50 cm aperture will be installed at behind the secondary mirror. The laser unit will be installed on the third floor of the dome and the laser beam will be transferred to the laser launching telescope using single mode photonic crystal fiber cable. The field of view of the optics is 2.7 arcmin to maximize the probability to find tilt guide stars for laser guide star operation. The expected Strehl ratio as raw AO performance is 0.46 at H-band under 0.60" seeing with 12 th mag guide star, and 0.71 for 8 th mag stars. New wavefront modulation technique, dual stroke membrane mirror control, is developed to reduce the tilt error which is more dominant for curvature sensor AO system. The superb contrast imaging capability will be expected as natural guide star system. The first light as the natural guide star system is planned in March 2006, the laser first light will be expected in March 2007.

Original languageEnglish (US)
Article number75
Pages (from-to)837-845
Number of pages9
JournalProceedings of SPIE - The International Society for Optical Engineering
Issue numberPART 2
StatePublished - 2004
EventAdvancements in Adaptive Optics - Glasgow, United Kingdom
Duration: Jun 21 2004Jun 25 2004


  • Adaptive optics
  • Curvature sensor
  • Laser guide star
  • Subaru telescope
  • Wavefront sensing

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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