Preliminary experiments of prototype laser guide star system for the Subaru telescope

Prototype laser guide star system for Subaru telescope has been developed at Communications Research Laboratory (CRL). The laser system comprises two commercially available lasers: a modified continuous wave (CW) dye laser and a 10 W all-solid CW laser of 532 nm wavelength for pumping the dye laser. The natural guide star adaptive optics system for Subaru telescope on Cassegrain focus will be upgraded to a laser guide star adaptive optics system using this laser system. The experiment of transmitting laser beam to the sodium layer is performed at CRL using a 1.5 m telescope. The laser beam is emitted from a 20 cm telescope mounted next to the 1.5 m telescope. A laser guide star is observed by a cooled CCD camera, which is equipped on the Nasmyth platform. We report the preliminary results of the experiment of observing a sodium laser guide star.