Hideki Takami (Subaru Telescope, National Astronomical Observatory of Japan), Stephen Colley (Subaru Telescope, National Astronomical Observatory of Japan), Matt Dinkins (Subaru Telescope, National Astronomical Observatory of Japan), Michael Eldred (Subaru Telescope, National Astronomical Observatory of Japan), Olivier Guyon (Subaru Telescope, National Astronomical Observatory of Japan), Taras Golota (Subaru Telescope, National Astronomical Observatory of Japan) Masayuki Hattori (Subaru Telescope, National Astronomical Observatory of Japan), Yutaka Hayano (Subaru Telescope, National Astronomical Observatory of Japan), Meguru Ito (Subaru Telescope, National Astronomical Observatory of Japan), Shin Oya (Subaru Telescope, National Astronomical Observatory of Japan), Yoshihiko Saito (Subaru Telescope, National Astronomical Observatory of Japan), Makoto Watanabe (Subaru Telescope, National Astronomical Observatory of Japan) Masanori Iye (National Astronomical Observatory of Japan)
Keywords: Adaptive Optics
Abstract:
Subaru Telescope has been operating 36 element curvature sensor AO system for the Cassegrain focus since 2000. We have developed a new AO system for the Nasmyth focus. The AO system has 188 element curvature wavefront sensor and bimorph deformable mirror. It is the largest format system for this type of sensor . The deformable mirror has also 188 element with 90 mm effective aperture and 130 mm blank size. The real time controller is 4 CPU real time Linux OS computer and the update speed is now 1.5 kHz. The AO system also has laser guide star system. The laser is sum frequency solid state laser generating 589 nm light. We have achieved 4.7 W output power with excellent beam quality of M^2=1.1 and good stability. The laser is installed in a clean room on the Nasmyth platform. The laser beam is transferred by photonic crystal optical fiber with 35 m to the 50 cm laser launching telescope mounted behind the Subaru 2ry mirror. The field of view of the low order wavefront sensor for tilt guide star in LGS mode is 2.7 arcmin in diameter. The AO system had the first light with natural guide star in October 2006. The Strehl ratio was > 0.5 at K band under the 0.8 arcsec visible seeing. We also has projected laser beam on the sky during the same engineering run. Three instruments will be used with the AO system. Infrared camera and spectrograph (IRCS), High dynamic range IR camera (HiCIAO) for exosolar planet detection, and visible 3D spectrograph.
Date of Conference: September 12-15, 2007
Track: Adaptive Optics