Ultra stable high power laser for the VIRGO project

However, a difficulty arises from the nature of stud- ied sparks. Since energy deposition from the discharge in the medium leads to strong hydrodynamic effects 21 , and because

In brief, an external perturbation is again added inside one of the loops (to the error signal in the Virgo configuration) and the transfer function from after the perturbation point

Lock acquisition of the recombined ITF: when the Fabry-Perot cavities are locked and the dark fringe power goes down a given threshold, usually half of the maximum power, the trigger

L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des

Finally, some solutions are proposed to further improve these performances, especially the absorption level (lower than 0.1 ppm) and the mechanical quality factor Q of the

The full Automatic Alignment system has been implemented since the C7 commissioning run, September 2005 2 , we are controlling all the mirror angular degrees of freedom with

As it will be explained, Virgo is not a bare Michelson interferometer; several optical components are used in addition to the classical 50% reflecting beam splitter (BS) and

The commissioning of Virgo started mid 2003 and has been performed in several steps: the alignment and the longitudinal controls of the Fabry-Perot cavities have first been