In-vacuum Faraday isolation remote tuning

none170sìIn-vacuum Faraday isolators (FIs) are used in gravitational wave interferometers to prevent the disturbance caused by light reflected back to the input port from the interferometer itself. The efficiency of the optical isolation is becoming more critical with the increase of laser input power. An in-vacuum FI, used in a gravitational wave experiment (Virgo), has a 20 mm clear aperture and is illuminated by an almost 20 W incoming beam, having a diameter of about 5 mm. When going in vacuum at 10−6 mbar, a degradation of the isolation exceeding 10 dB was observed. A remotely controlled system using a motorized λ=2 waveplate inserted between the first polarizer and the Faraday rotator has proven its capability to restore the optical isolation to a value close to the one set up in air.mixed Accadia T; Acernese F; Antonucci F; Aoudia S; Arun KG; Astone P; Ballardin G; Barone F; Barsuglia M; Bauer TS; Beker MG; Bigotta S; Birindelli S; Bitossi M; Bizouard MA; Blom M; Boccara C; Bondu F; Bonelli L; Bosi L; Braccini S; Bradaschia C; Brillet A; Brisson; Budzynski R; Bulik T; Bulten HJ; Buskulic D; Cagnoli G; Calloni E; Campagna E; Canuel B; Carbognani F; Cavalier F; Cavalieri R; Cella G; Cesarini E; Chassande-Mottin E; Chincarini A; Cleva F; Coccia E; Colacino CN; Colas J; Colla A; Colombini M; Corda C; Corsi A; Coulon JP; Cuoco E; D'Antonio S; Dari A; Dattilo V; Davier M; Day R; De Rosa R; del Prete M; Di Fiore L; Di Lieto A; Emilio MD; Di Virgilio A; Dietz A; Drago M; Fafone V; Ferrante I; Fidecaro F; Fiori I; Flaminio R; Fournier JD; Franc J; Frasca S; Frasconi F; Freise A; Gammaitoni L; Garufi F; Gemme G; Genin E; Gennai A; Giazotto A; Gouaty R; Granata M; Greverie C; Guidi GM; Heitmann H; Hello P; Hild S; Huet D; Jaranowski P; Kowalska I; Królak A; La Penna P; Leroy N; Letendre N; Li TG; Lorenzini M; Loriette V; Losurdo G; Mackowski JM; Majorana E; Man N; Mantovani M; Marchesoni F; Marion F; Marque J; Martelli F; Masserot A; Michel C; Milano L; Minenkov Y; Mohan M; Moreau J; Morgado N; Morgia A; Mosca S; Moscatelli V; Mours B; Neri I; Nocera F; Pagliaroli G; Palladino L; Palomba C; Paoletti F; Pardi S; Parisi M; Pasqualetti A; Passaquieti R; Passuello D; Persichetti G; Pichot M; Piergiovanni F; Pietka M; Pinard L; Poggiani R; Prato M; Prodi GA; Punturo M; Puppo P; Rabaste O; Rabeling DS; Rapagnani P; Re V; Regimbau T; Ricci F; Robinet F; Rocchi A; Rolland L; Romano R; Rosińska D; Ruggi P; Sassolas B; Sentenac D; Sturani R; Swinkels B; Toncelli A; Tonelli M; Tournefier E; Travasso F; Trummer J; Vajente G; van den Brand JF; van der Putten S; Vavoulidis M; Vedovato G; Verkindt D; Vetrano F; Viceré A; Vinet JY; Vocca H; Was M; Yvert M; Virgo C accadia, T;  acernese, F;  antonucci, F;  aoudia, S;  arun, Kg;  astone, P;  ballardin, G;  barone, F;  barsuglia, M;  bauer, Ts;  beker, Mg;  bigotta, S;  birindelli, S;  bitossi, M;  bizouard, Ma;  blom, M;  boccara, C;  bondu, F;  bonelli, L;  bosi, L;  braccini, S;  bradaschia, C;  brillet, A;  brisson, ;  budzynski, R;  bulik, T;  bulten, Hj;  buskulic, D;  cagnoli, G;  calloni, E;  campagna, E;  canuel, B;  carbognani, F;  cavalier, F;  cavalieri, R;  cella, G; Cesarini, Elisabetta;  Chassande Mottin, E;  chincarini, A;  cleva, F;  coccia, E;  colacino, Cn;  colas, J;  colla, A;  colombini, M;  corda, C;  corsi, A;  coulon, Jp;  cuoco, E;  d'Antonio, S;  dari, A;  dattilo, V;  davier, M;  day, R;  De Rosa, R;  del Prete, M;  Di Fiore, L;  Di Lieto, A;  emilio, Md;  Di Virgilio, A;  dietz, A;  drago, M;  fafone, V;  ferrante, I;  fidecaro, F;  fiori, I;  flaminio, R;  fournier, Jd;  franc, J;  frasca, S;  frasconi, F;  freise, A;  gammaitoni, L;  garufi, F;  gemme, G;  genin, E;  gennai, A;  giazotto, A;  gouaty, R;  granata, M;  greverie, C; Guidi, GIANLUCA MARIA;  heitmann, H;  hello, P;  hild, S;  huet, D;  jaranowski, P;  kowalska, I;  królak, A;  La Penna, P;  leroy, N;  letendre, N;  li, Tg;  lorenzini, M;  loriette, V;  losurdo, G;  mackowski, Jm;  majorana, E;  man, N;  mantovani, M;  marchesoni, F;  marion, F;  marque, J; Martelli, Filippo;  masserot, A;  michel, C;  milano, L;  minenkov, Y;  mohan, M;  moreau, J;  morgado, N;  morgia, A;  mosca, S;  moscatelli, V;  mours, B;  neri, I;  nocera, F;  pagliaroli, G;  palladino, L;  palomba, C;  paoletti, F;  pardi, S;  parisi, M;  pasqualetti, A;  passaquieti, R;  passuello, D;  persichetti, G;  pichot, M; Piergiovanni, Francesco;  pietka, M;  pinard, L;  poggiani, R;  prato, M;  prodi, Ga;  punturo, M;  puppo, P;  rabaste, O;  rabeling, Ds;  rapagnani, P;  re, V;  regimbau, T;  ricci, F;  robinet, F;  rocchi, A;  rolland, L;  romano, R;  rosińska, D;  ruggi, P;  sassolas, B;  sentenac, D; Sturani, Riccardo;  swinkels, B;  toncelli, A;  tonelli, M;  tournefier, E;  travasso, F;  trummer, J;  vajente, G;  van den Brand, Jf;  van der Putten, S;  vavoulidis, M;  vedovato, G;  verkindt, D; Vetrano, Flavio; Vicere', Andrea;  vinet, Jy;  vocca, H;  was, M;  yvert, M; Virgo, C

In-vacuum Faraday isolation remote tuning

In-vacuum Faraday isolators (FIs) are used in gravitational wave interferometers to prevent the disturbance caused by light reflected back to the input port from the interferometer itself. The efficiency of the optical isolation is becoming more critical with the increase of laser input power. An in-vacuum FI, used in a gravitational wave experiment (Virgo), has a 20 mm clear aperture and is illuminated by an almost 20 W incoming beam, having a diameter of about 5 mm. When going in vacuum at 10(-6) mbar, a degradation of the isolation exceeding 10 dB was observed. A remotely controlled system using a motorized lambda/2 waveplate inserted between the first polarizer and the Faraday rotator has proven its capability to restore the optical isolation to a value close to the one set up in air. c 2010 Optical Society of Americ