Atomic transitions for adaptive optics

Abstract

This paper reviews atoms and ions in the upper atmosphere, including the mesospheric metals Na, Fe, Mg${}^{+}$, Si${}^{+}$, Ca${}^{+}$, K and also non-metallic species N, N${}^{+}$, O, H, considering their potential for astronomical adaptive optics. Na and Fe are the best candidates for the creation of polychromatic laser guide stars, with the strongest returns coming from transitions that can be reached by excitation at two wavelengths. Ca${}^{+}$ and Si${}^{+}$ have strong visible-light transitions, but require short wavelengths, beyond the atmospheric cutoff, for excitation from the ground state. Atomic O, N and N${}^{+}$ have strong transitions and high abundances in the mesosphere. The product of column density and cross section for these species can be as high as $10^5$ for O and several hundred for N and N${}^{+}$, making them potential candidates for amplified spontaneous emission. However they require vacuum-ultraviolet wavelengths for excitation.

arXiv comment18 pages, 8 figures

References in corpus (5)

• Optimization of cw sodium laser guide star efficiency
• Observations of O (1S) and O (1D) in Spectra of C/1999 S4 (LINEAR)
• Towards optimization of pulsed sodium laser guide stars
• Temporal variability of the telluric sodium layer
• Can amplified spontaneous emission produce intense laser guide stars for adaptive optics?

Cited by in corpus (1)

• Laser guide star return-flux gain from frequency chirping