Passive optical resonator for OSQAR LSW experiment

This paper treats the issue of locking a solid state laser, pumped by high power diodes (Verdi V5), to a twenty meter long optical resonator for OSQAR LSW - light shining through the wall, dark matter search experiment. In this paper the optical design and a possible locking scheme are presented. The environmental conditions in SM18 testing hall at CERN, where OSQAR experiment is based, are discussed. The main focus is put on the vibration analysis, cavity transversal modes behaviour, possible clipping in the anticryostat of LHC – Large Hadron Collider magnet bore and locking loop parameters required for future experimental testing. The expected finesse of resonator will be presented and discussed in the sense of OSQAR LSW; its impact on possible new exclusion limits is discussed.