%% Units & Constants for convenience ppm=1e-6; nm=1e-9; pm=1e-12; MHz = 1e6; percent = 1/100; c=299792458; lambda=1.0640e-06; p.lambda = lambda; %% Arm Asymmetries % Asymmetry in the reflectivities p.armAsym = p.notperfect*1*percent; % Asymmetry of the round trip loss p.ArmLossAsym = p.notperfect*15*ppm; p.BSasym = p.notperfect*0.01; %BS reflectivity asymmetry p.ITMasym = p.notperfect*p.armAsym; %ITM reflectivity asymmetry p.ETMasym = p.notperfect*p.armAsym; %ETM reflectivity asymmetry %% -------- The Main IFO Mirror parameters ---------- %ITMs p.ITMXaio = 0; p.ITMXChr = 1/1900; % 1/ROC of ITMX %p.ITMXThr = 0.004*(1+p.ITMasym/2)-45*ppm; %ITMX transmission %p.ITMXLhr = 45*ppm; %ITMX HR Loss p.ITMXThr = 0.004; p.ITMXLhr = 45*ppm+p.ArmLossAsym; p.ITMXRar = p.ARreflective*200*ppm; %ITMX AR Reflection (for POX). p.ITMXLmd = 0; % Ignore the substrate loss. p.ITMXNmd = 1.754; %Index of refraction p.ITMYaio = 0; p.ITMYChr = 1/1900; % 1/ROC of ITMY %p.ITMYThr = 0.004*(1-p.ITMasym/2)-45*ppm; %ITMY transmission %p.ITMYLhr = 45*ppm; %ITMY HR Loss p.ITMYThr = 0.004; p.ITMYLhr = 45*ppm-p.ArmLossAsym; p.ITMYRar = p.ARreflective*200*ppm; %ITMY AR Reflection (for POY). p.ITMYLmd = 0; % Ignore the substrate loss. p.ITMYNmd = 1.754; %Index of refraction %ETMs p.ETMXaio = 0; p.ETMXChr = 1/1900; % 1/ROC of ETMX p.ETMXLhr = 45*ppm+p.ArmLossAsym; %ETMX HR Loss p.ETMXThr = 10*ppm; %ETMX transmission p.ETMXRar = 0*ppm; %ETMX AR Reflection (ignore). p.ETMXLmd = 0; % Ignore the substrate loss. p.ETMXNmd = 1.754; %Index of refraction p.ETMYaio = 0; p.ETMYChr = 1/1900; % 1/ROC of ETMY p.ETMYLhr = 45*ppm-p.ArmLossAsym; %ETMY HR Loss p.ETMYThr = 10*ppm; %ETMY transmission p.ETMYRar = 0*ppm; %ETMY AR Reflection (ignore). p.ETMYLmd = 0; % Ignore the substrate loss. p.ETMYNmd = 1.754; %Index of refraction %BS p.BSaio = 45; p.BSChr = 0; % 1/ROC of BS p.BSThr = 0.5*(1+p.BSasym); %BS transmission p.BSLhr = 100*ppm; %BS HR Loss p.BSRar = p.ARreflective*50*ppm; %BS AR Reflection (for POB). p.BSLmd = 0; % Ignore the substrate loss. p.BSNmd = 1.45; %Index of refraction %PRM p.PRMaio = 0; p.PRMChr = 1/458.128519465; % 1/ROC of PRM p.PRMThr = 0.10;%(1-0.87); %PRM transmission p.PRMLhr = 45*ppm; %PRM HR Loss p.PRMRar = p.ARreflective*50*ppm; %PRM AR Reflection p.PRMLmd = 0; % Ignore the substrate loss. p.PRMNmd = 1.45; %Index of refraction %PR2 p.PR2aio = 0.6860; p.PR2Chr = 1.0/-3.0764084715; % 1/ROC of PR2 p.PR2Thr = 500*ppm; %PR2 transmission p.PR2Lhr = 100*ppm; %PR2 HR Loss p.PR2Rar = 0; %PR2 AR Reflection (ignore). p.PR2Lmd = 0; % Ignore the substrate loss. p.PR2Nmd = 1.45; %Index of refraction %PR3 p.PR3aio = 0.6860; p.PR3Chr = 1.0/24.9164838708; % 1/ROC of PR3 p.PR3Thr = 50*ppm; %PR3 transmission p.PR3Lhr = 100*ppm; %PR3 HR Loss p.PR3Rar = 0; %PR3 AR Reflection (ignore). p.PR3Lmd = 0; % Ignore the substrate loss. p.PR3Nmd = 1.45; %Index of refraction %SRM p.SRMaio = 0; p.SRMChr = 1/458.128519465; % 1/ROC of SRM %p.SRMThr = 0.1536-45*ppm; %SRM transmission p.SRMThr = 0.15-45*ppm; %SRM transmission %p.SRMThr = 0.50-45*ppm;%0.15-45*ppm; %SRM transmission p.SRMLhr = 45*ppm; %SRM HR Loss p.SRMRar = p.ARreflective*50*ppm; %SRM AR Reflection. p.SRMLmd = 0; % Ignore the substrate loss. p.SRMNmd = 1.45; %Index of refraction %SR2 p.SR2aio = 0.6860; p.SR2Chr = 1.0/-2.98718007727; % 1/ROC of SR2 p.SR2Thr = 50*ppm; %SR2 transmission p.SR2Lhr = 100*ppm; %SR2 HR Loss p.SR2Rar = 0; %SR2 AR Reflection (ignore). p.SR2Lmd = 0; % Ignore the substrate loss. p.SR2Nmd = 1.45; %Index of refraction %SR3 p.SR3aio = 0.6860; p.SR3Chr = 1.0/24.9164838708; % 1/ROC of SR3 p.SR3Thr = 50*ppm; %SR3 transmission p.SR3Lhr = 100*ppm; %SR3 HR Loss p.SR3Rar = 0; %SR3 AR Reflection (ignore). p.SR3Lmd = 0; % Ignore the substrate loss. p.SR3Nmd = 1.45; %Index of refraction %% ------------ Main IFO Lengths ---------------------- %Arm Cavity Length p.Larm=3000; %PRC length p.Lprc=66.5913279884; %SRC length p.Lsrc=66.5913279884; %16.88MHz %Schnupp asymmetry p.Las=3.3299; %16.88MHz %PRC length p.LPRM_PR2 = 14.7614883609; %Distance between PRM and PR2 p.LPR2_PR3 = 11.0660636313; %Distance between PR2 and PR3 p.LPR3_BS = 15.7637759961; %Distance between PR3 and BS %Michelson part %Average length of the Michelson arms p.LMIavg = p.Lprc - (p.LPRM_PR2 + p.LPR2_PR3 + p.LPR3_BS); p.LBS_ITMX=p.LMIavg + p.Las/2; % Michelson X arm p.LBS_ITMY=p.LMIavg -p.Las/2; % Michelson Y arm %SRC lengths p.LSR2_SR3 = 11.1115048847; %Distance between SR2 and SR3 p.LSR3_BS = 15.7385994361; %Distance between SR3 and BS p.LSRM_SR2 = p.Lsrc - (p.LSR2_SR3+p.LSR3_BS+p.LMIavg); %Distance between SRM and SR2 %% Operating Point % Operating points of the recycling mirrors. % In the Optickle convention, the front refrection has a negative % negative reflectivity. This means, the PRM has a negative reflectivity % for the fields inside the PRC whereas the ITMs have positive reflectivities % for them. The two folding mirrors have negative reflectivities but they % cancel out. So, the PRC naturally becomes anti-resonant to the carrier % in the absence of the ETMs. This is what we want. % No need to tweak the PRM position. % The situation is the same for the SRC, but it is not what we want. % For SRC, we have to make it resonant to the carrier by itself because % we want to lower the effective reflectivity of the ITMs seen from the % fields inside the arm cavities with differential phase shifts between % the two arms. In order to compensate for the negative reflectivity of % the ITM back, we shift the microscopic position of the SRM by a quater % of the wavelength (a half-wavelength change for a round trip). p.posOffsetPRM=0; p.posOffsetSRM=lambda/4; % MICH offset p.MICHoffset = 0*pm; % Arm offset for DC readout % This value will be overwritten by the automatic HD phase adjustment routine. p.armOffsetPolarity = 1; p.armOffset = p.armOffsetPolarity * p.DCReadout * 0.5*pm; %% AS pick off p.ASPOMaio = 45; p.ASPOMChr = 0; % 1/ROC of AS Pickoff p.ASPOMThr = 0.99; % 1% pickoff p.ASPOMLhr = 100*ppm; %OMC1 HR Loss p.ASPOMRar = 0; %AR Reflection (ignore). p.ASPOMLmd = 0; % Ignore the substrate loss. p.ASPOMNmd = 1.45; %Index of refraction %% ------------ OMC Params ------------------- % Here, OMC is modeled as a straight Fabry-Perot, % which is not the case for the real LCGT. % But it doesn't matter for now. %OMC1 p.OMC1aio = 1; p.OMC1Chr = 1/1.5; % 1/ROC of OMC1 p.OMC1Thr = 0.00157; %OMC1 transmission, Finesse = 2000 p.OMC1Lhr = 10*ppm; %OMC1 HR Loss p.OMC1Rar = 0; %AR Reflection (ignore). p.OMC1Lmd = 0; % Ignore the substrate loss. p.OMC1Nmd = 1.45; %Index of refraction %OMC2 p.OMC2aio = 1; p.OMC2Chr = 1/1.5; % 1/ROC of OMC2 p.OMC2Thr = 0.00157; %OMC2 transmission, Finesse = 2000 p.OMC2Lhr = 10*ppm; %OMC2 HR Loss p.OMC2Rar = 0; %AR Reflection (ignore). p.OMC2Lmd = 0; % Ignore the substrate loss. p.OMC2Nmd = 1.45; %Index of refraction p.LOMC = 1.0; %FSR = 150MHz %% Reset Demodulation Phases p.MZdemod=0; p.dpREFL1=0; p.dpREFL2=0; p.dpREFL1Dp=0; p.dpREFL1Dm=0; p.dpREFL2Dp=0; p.dpREFL2Dm=0; p.dpREFL1Th=0; p.dpREFL2Th=0; p.dpASPO1=0; p.dpAS1=0; p.dpAS2=0; p.dpASDDp=0; p.dpASDDm=0; p.dpPOX1=0; p.dpPOY1=0; p.dpPOP1=0; p.dpPOP2=0; p.dpPOP1Th=0; p.dpPOP2Th=0; %% Mechanical TFs %Test mass parameters mTM = 22.8; rTM = 0.22/2; dTM = 0.15; QTM = 1e5; %Mechanical Q of the TM pendulum wTM = sqrt(9.8/0.4); %Pendulum freq. InTM = (rTM^2/4 + dTM^2/12)*mTM; %Moment of innertia wTMPit = 2*pi*1.0; %Pit resonant freq. QTMPit = 1e5; p.tfTM = zpk([], -wTM*[1/(2*QTM) + sqrt((1/(2*QTM))^2 - 1), ... 1/(2*QTM) - sqrt((1/(2*QTM))^2 - 1)], 2/mTM); %2/mTM should in principle be 1/mTM. %However, 1/mTM does not match the %theoretica radiation pressure noise p.tfTMPit = zpk([], -wTMPit*[1/(2*QTMPit) + sqrt((1/(2*QTMPit))^2 - 1), ... 1/(2*QTMPit) - sqrt((1/(2*QTMPit))^2 - 1)], 2/InTM); %BS parameters mBS = 20; rBS = 0.38/2; dBS = 0.08; QBS = 1e5; %Mechanical Q of the TM pendulum wBS = sqrt(9.8/0.4); %Pendulum freq. InBS = (rBS^2/4 + dBS^2/12)*mBS; %Moment of innertia wBSPit = 2*pi*1.0; %Pit resonant freq. QBSPit = 1e5; p.tfBS = zpk([], -wBS*[1/(2*QBS) + sqrt((1/(2*QBS))^2 - 1), ... 1/(2*QBS) - sqrt((1/(2*QBS))^2 - 1)], 2/mBS); p.tfBSPit = zpk([], -wBSPit*[1/(2*QBSPit) + sqrt((1/(2*QBSPit))^2 - 1), ... 1/(2*QBSPit) - sqrt((1/(2*QBSPit))^2 - 1)], 2/InBS); %PRM, SRM, PR2, SR2, PR3, SR3 mPRM = 10.8; rPRM = 0.25/2; dPRM = 0.1; QPRM = 1e5; %Mechanical Q of the TM pendulum wPRM = sqrt(9.8/0.4); %Pendulum freq. InPRM = (rPRM^2/4 + dPRM^2/12)*mPRM; %Moment of innertia wPRMPit = 2*pi*1.0; %Pit resonant freq. QPRMPit = 1e5; p.tfPRM = zpk([], -wPRM*[1/(2*QPRM) + sqrt((1/(2*QPRM))^2 - 1), ... 1/(2*QPRM) - sqrt((1/(2*QPRM))^2 - 1)], 2/mPRM); p.tfPRMPit = zpk([], -wPRMPit*[1/(2*QPRMPit) + sqrt((1/(2*QPRMPit))^2 - 1), ... 1/(2*QPRMPit) - sqrt((1/(2*QPRMPit))^2 - 1)], 2/InPRM); p.tfSRM = p.tfPRM; p.tfSRMPit = p.tfPRMPit; p.tfPR2 = p.tfPRM; p.tfPR2Pit = p.tfPRMPit; p.tfSR2 = p.tfSRM; p.tfSR2Pit = p.tfSRMPit; p.tfPR3 = p.tfPRM; p.tfPR3Pit = p.tfPRMPit; p.tfSR3 = p.tfSRM; p.tfSR3Pit = p.tfSRMPit; %% Scattering Light Parameters % Whether to do SCL injection or not. p.do_SCL = false; %Scattered light amplitudes p.EsETMX = 0; p.EsPR2 = 0; p.EsPRMAR = 0; p.EsREFL = 0; p.EsSR2 = 0; p.EsSRMAR = 0; p.EsITMtoBS = 0; p.EsITMAR = 0; %MICH PO transmissivity p.MICHX_POThr =1-100*ppm; %REFL PO transmissivity p.REFL_POThr =1-100*ppm; % Position offset of steering mirrors % before the scattered light injection. % This is used to change the relative phase % of the scattered light with the main carrier. p.SCL_ETMX_OFS = 0; p.SCL_PR2_OFS = 0; p.SCL_PRMAR_OFS = 0; p.SCL_SR2_OFS = 0; p.SCL_SRMAR_OFS = 0; p.SCL_ITMtoBS_OFS = 0; p.SCL_ITMAR_OFS = 0; p.SCL_REFL_OFS = 0; %% Misc parameters % Attenuators before PDs p.REFL_ATTN = 0; p.POP_ATTN = 0; % BS reflectivities for REFL port to set the power ratio % of the REFL PDs p.REFLBS1_R = 1 - 1/4; p.REFLBS2_R = 1/3; p.REFLBS3_R = 1/2; % BS reflectivities for POP port to set the power ratio % of the POP PDs p.POPBS1_R = 1/2; % Quantum efficiency of the PDs p.Qeff = 0.9; % Max power at RF PD p.PpdMax = 0.05; %50mW %Whether to tickle or not p.doTickle = 1; % PD dynamic range p.RFPDDrange = 1e8; p.DCPDDrange = 5e9; % Whether to calculate Loop Noise or not p.LoopNoise = 1; % Whether to do tickle with the optics fixed p.doFixedTickle = 0; % MICH actuation method, whether to actuate on BS or ITM+ETMs p.MICHBS = 0; % Whether to calculate the RFPD requirements or not p.calc_RFPD_requirements = 1; % RMS of each DOF after the suppression by the servo p.DARM_RMS =1e-12; p.CARM_RMS =0.1e-12; p.MICH_RMS =1e-12; p.PRCL_RMS =1e-12; p.SRCL_RMS =1e-12;