High-order laser guide star performance for the Euro50 telescope

Abstract:
High-order laser guide star performance for the Euro50 telescope is analyzed. Focus anisoplanatism residual errors using multiple LGSs are obtained by numerical simulations. Results calculated for annual mean conditions at the La Palma site show that, considering only focus anisoplanatism, it will be possible to obtain a Strehl ratio of 0.72 similar to 0.82 at 2.2 mum using 13 LGSs. A Strehl ratio of 0.60 similar to 0.70 can be obtained at 1.25 mum using 21 LGSs. The dependence of wavefront measurement error on pulsed laser power is also investigated. The variance of the measurement error is lower than 0.2 rad(2) when the laser power is larger than 14 W.