<title>Comparison of multiconjugate adaptive optics configurations and control algorithms for the Gemini South 8-m telescope</title>

Abstract

This paper focuses on two main categories of the multiconjugate adaptive optics (MCAO) parameter space for performance optimization: the geometrical configuration of guide stars and deformable mirrors (DMs) , and the wavefront reconstructors. From the first category it is shown how, for a fixed reconstructor and imaging wavelength, the performance metrics with a few important exceptions improve with an increasing number of i) DMs, ii) actuators per DM and iii) guide stars. The metrics are seen to degrade with i) an increasing field of compensation and ii) DM conjugation altitude mismatch with the significant turbulent atmospheric layers. In the second category, this study also compares the performance with a fixed MCAO configuration using the least-square estimator (LSE) and the maximum a posteriori estimator (MAP) for wavefront reconstruction. The MAP is shown to perform significantly better than the LSE at low or intermediate signal-to-noise ratios (SNRs) , and somewhat better even in the absence of noise due to its a priori knowledge of the phase statistics.

Monte Carlo modelling of multiconjugate adaptive optics performance on the European Extremely Large Telescope

“…We find that our estimated performance for basic models is broadly similar to other ELT Monte-Carlo models (Le Louarn et al 2012;Tallon et al 2011;Foppiani et al 2010), and slightly pessimistic when compared with analytical models of AO performance (Neichel et al 2008), as expected. The consideration of DM conjugation is largely independent of telescope diameter, and our results are similar to those given by Femenía & Devaney (2003); Flicker et al (2000). Similarly, a study of LGS pixel count was carried out by van Dam et al (2011).…”

MCAO for Gemini South

“…The expected performance of the MCAO system parameters described in Table 1 has been optimized and evaluated through trade studies involving a variety of adaptive optics analysis and simulation codes 3,4,5 . The predicted RMS wavefront error with median seeing and bright natural guide stars is 252 nm, which corresponds to Strehl ratios of 0.20, 0.40, and 0.60 in the J, H, and K spectral bands.…”

Multi-mirror adaptive optics for control of thermally induced aberrations in extreme ultraviolet lithography

“…5,6 The assumption that additional deformable mirror surfaces improve the performance is supported by literature on MCAO. 7 The aim of this study is twofold. First, we evaluate different MMAO configurations by means of a simulation model of a patented POB design.…”