PVLAS Developments on Fabry-Perot Resonators Locked to CW Lasers and Suitable for Laser Assisted Lorentz Stripping of H– Beams

The PVLAS experiment, running at the Legnaro National Laboratory of INFN (Padova, Italy), is operating a 6.4 m long, 10^5 finesse Fabry‐Perot (FP) cavity frequency locked to a 1064 nm, 100 mW output power Nd:YAG infrared laser. This cavity has a quality factor greater than 1012, and is kept at resonance for periods of time in excess of several hours. A 100 mW, 532 nm, laser has been recently locked to an 87 cm long FP cavity with a finesse of 45000. Light power density at the center of this resonator was 1200 W/cm^2. Short term plans of the PVLAS experiment foresee the installation of a 6.4 m long, 10^5 finesse, Fabry‐Perot resonator operating at 532 nm. Dedicated developments with a 532 nm, 5 W, input laser would provide a 10 kW/cm^2 power density, over a 1 cm^2 cross section, useful for laser assisted H− full stripping