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Title: Desing of a Laser Guide Star System for the Keck II Telescope

Conference ·
OSTI ID:600576

A laser guide star system similar to that deployed at the Lick Observatory has been designed for the Keck II 10 m telescope on Mauna Kea, Hawaii. The subaperature size on the primary is comparable to that at Lick, and at the same observational wavelength centered about the K band, so that the average power requirements of the laser system are also comparable, at about 20 W. One major difference is that the seeing at Mauna Kea is about a factor of two better than at Lick so that the spot diameter requirements are smaller and this can give rise to reduced back scatter resulting from saturation effects in the sodium layer. To reduce the peak flux in the sodium layer and obtain a smaller spot diameter, the output beam diameter has been increased along with the repetition rate of the laser. As with the Lick laser system, a dye laser is pumped by a series of frequency doubled YAG lasers which are remotely located and coupled to the dye laser on the telescope by optical fibers. The laser system has a full set of beam control optics as well as launch telescope and safety systems. A computer system couples the laser system to the User Interface and Supervisory Control system of the main telescope. The laser system is due to be shipped to Keck during the fall of 1997 where it will be integrated with the telescope at Mauna Kea. The Adaptive Optics and Optics Bench systems will be integrated first and be ready for integration with the laser in the summer of 1998. 1 ref., 8 figs.

Research Organization:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
600576
Report Number(s):
UCRL-JC-128570; CONF-9706204-; ON: DE98051379
Resource Relation:
Conference: Laser Guide Star Workshop, Garching bei Munich (Germany), 22-27 Jun 1997; Other Information: PBD: 11 Sep 1997
Country of Publication:
United States
Language:
English