Sprecher
Beschreibung
Bivoj laser system is located at Hilase center near Prague, Czechia. It incorporates two adaptive optics systems (AOS). One for each of its two cryogenically cooled main amplifiers, both of which work with a square flat-top beam profile. First AOS deals with aberrations of the 10J amplifier with beam size of 21.5 x 21.5 mm2 and composes of a bimorph Deformable Mirror (DM) and a Quadri-wave Lateral Shearing Interferometer (QLSI). Second AOS is incorporated in the 100J amplifier and deals with beam size of 75 x 75 mm2. While the 10J loop performance is stable, the 100 J loop is not. The standing problem of the latter amplifier is related to helium gas fluctuations of its cooling system that dynamically changes the output beam wavefront and corresponding far field. To address this problem a detailed analysis of these fluctuations was performed using a CW probe beam in order to obtain a higher framerate signal. Results of this analysis as well as relevant simulations will be discussed.
