Arm Length Stabilization Conceptual Configuration JGW-T1605353 May 10, 2019 Arm Length Stabilization Conceptual Configuration Yuta Michimura Department of Physics, University of Tokyo

Candidate1 (aLIGO-like) 40 MHz ~ offset 80 MHz PDH ~ ALS DIFF AUX X ~ PLL 80 MHz offset ALS COMM SHG PSL IMC FSS AOM PDH Ref Cav AOM ~ ~ 80 MHz 40 MHz 80 MHz ~ PDH AUX Y PLL

Candidate2 (simplified-aLIGO) 40 MHz ~ offset 40 MHz PDH ~ ALS DIFF AUX X ~ PLL 40 MHz offset ALS COMM PSL IMC FSS PDH Ref Cav AOM ~ 80 MHz 40 MHz ~ PDH AUX Y PLL

Candidate3 (Tatsumi/Arai/Aso) 40 MHz ~ offset PDH AOM AUX X PLL PSL IMC FSS PDH Ref Cav AOM ~ 80 MHz 40 MHz ~ offset PDH AOM AUX Y PLL

Candidate4 (hybrid) ~ ~ ~ 40 MHz offset PDH ALS DIFF AOM AUX X PLL ALS COMM PSL IMC FSS PDH Ref Cav AOM ~ 80 MHz 40 MHz ~ offset PDH AOM AUX Y PLL

Considerations Where to put PLL setup for PSL vs AUX X/Y Where to put green beat setup for ALS COMM Where to put green beat setup for ALS DIFF Plan 1: All at PSL clean booth - need two fibers to send AUX green to POS/POP table - enough space for optics at PSL table? [Nakano] - enough space for electronics at IOO racks? [Michimura] -> yes Plan 2: AUX X at POP, AUX Y at POS - need two fibers to send PSL green to POS/POP table beat for PLL also with green? - need one fiber to send AUX X green to POS - enough space for electronics at ISC racks? [Michimura] -> yes

Setup for Table-Top Experiment? Conceptual drawing made by Kambara to be fixed [Kambara]

Schedule to be fixed [Matsushima] very rough schedule 2016.7-10: ALS design 2016.10-2017.9: Table-top experiment at Univ. Toyama 2017.5-2017.6: BRT installation at Kamioka 2017.6: PRs and BS ready (no ETM yet) 2017.7?-??: GreenX installation at Kamioka? 2017.10-2018.3: GreenX/Y installation at Kamioka ? 2018.8: ITM/ETM CRYp installation complete 2018.9-: ALS experiment at Kamioka

Releated References aLIGO configuration https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=11083 http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=1895 Study by Tasumi-san et al. in 2011-2012 https://granite.phys.s.u-tokyo.ac.jp/svn/Private/trunk/LCGTbackup/GreenLock/ http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=788 http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=1268