Sodium-layer laser-guide-star experimental results
| Autor: | Herbert W. Friedman, J. M. Duff, D. A. Rapp, Kenneth Avicola, Horst D. Bissinger, Donald T. Gavel, J. R. Morris, J. T. Salmon, Scot S. Olivier, James M. Brase, Kenneth E. Waltjen, R. W. Presta, Claire E. Max |
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| Rok vydání: | 1994 |
| Předmět: |
Physics
business.industry Irradiance Sodium layer Laser Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention Optics Laser guide star law Physics::Atomic Physics Computer Vision and Pattern Recognition Guide star Laser power scaling business Adaptive optics Atomic vapor laser isotope separation |
| Zdroj: | Journal of the Optical Society of America A. 11:825 |
| ISSN: | 1520-8532 1084-7529 |
| Popis: | We describe a series of experiments to characterize the sodium-layer guide star that was formed with the high-power laser developed for the Lawrence Livermore National Laboratory Atomic Vapor Laser Isotope Separation program. An emission spot size of 3.0 m was measured, with an implied laser irradiance spot diameter of 2.0 m. The rms spot motion at the higher laser powers, with active beam-pointing control, was less than 0.5 arcsec and had little effect on the observed spot size under these conditions. We measured the resonant backscatter from the sodium layer as a function of laser power to obtain a saturation curve. With a transmitted power of 1100 W and an atmospheric transmission of 0.6, the irradiance from the guide star at the ground was 10 (photons/cm2)/ms, corresponding to a visual magnitude of 5.1. The implications for the performance of wave-front sensors with a laser guide star of this magnitude and resulting closed-loop adaptive-optics performance are discussed. |
| Databáze: | OpenAIRE |
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