%% 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 = 1*percent;

% Asymmetry of the round trip loss
p.ArmLossAsym = p.notperfect*10*ppm;

p.BSasym = p.notperfect*p.armAsym; %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 = 1/7300; % 1/ROC of ITMX
p.ITMXThr = 0.004*(1+p.notperfect*p.ITMasym/2)-45*ppm; %ITMX transmission
p.ITMXLhr = 45*ppm; %ITMX HR Loss
p.ITMXRar = p.ARreflective*50*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 = 1/7300; % 1/ROC of ITMY
p.ITMYThr = 0.004*(1-p.notperfect*p.ITMasym/2)-45*ppm; %ITMY transmission
p.ITMYLhr = 45*ppm; %ITMY HR Loss
p.ITMYRar = p.ARreflective*50*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 = 1/7300; % 1/ROC of ETMX
p.ETMXLhr = 45*ppm+p.ArmLossAsym/2; %ETMX HR Loss
p.ETMXThr = 55*ppm*(1+p.ETMasym/2)-45*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 = 1/7300; % 1/ROC of ETMY
p.ETMYLhr = 45*ppm-p.ArmLossAsym/2; %ETMY HR Loss
p.ETMYThr = 55*ppm*(1-p.ETMasym/2)-45*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 = 1/337.1; % 1/ROC of PRM
p.PRMThr = (1-0.9)-45*ppm; %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 = 1;
p.PR2Chr = -1/3.9; % 1/ROC of PR2
p.PR2Thr = 50*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 = 1;
p.PR3Chr = 1/32; % 1/ROC of PR3
p.PR3Thr = 500*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 = 1/337.1; % 1/ROC of SRM
p.SRMThr = 0.1536-45*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 = 1;
p.SR2Chr = -1/3.9; % 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 = 1;
p.SR3Chr = 1/32; % 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=73.2826;

%SRC length
p.Lsrc=73.2826;  %11.25MHz 

%Schnupp asymmetry
p.Las=3.33103; %11.25MHz
%p.Las=0.5; %11.25MHz


%PRC lengths
p.LPRM_PR2 = 17.1; %Distance between PRM and PR2
p.LPR2_PR3 = 14.1; %Distance between PR2 and PR3
p.LPR3_BS = 17.1; %Distance between PR3 and BS

%SRC lengths
p.LSRM_SR2 = 17.1; %Distance between SRM and SR2
p.LSR2_SR3 = 14.1; %Distance between SR2 and SR3
p.LSR3_BS = 17.1; %Distance between SR3 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

%% 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.armOffset =  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.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;

%% Mechanical TFs

%Test mass parameters

mTM = 30;
rTM = 0.25/2;
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)], 1/mTM);
                  
p.tfTMPit = zpk([], -wTMPit*[1/(2*QTMPit) + sqrt((1/(2*QTMPit))^2 - 1), ...
                      1/(2*QTMPit) - sqrt((1/(2*QTMPit))^2 - 1)], 1/InTM);

%BS parameters

mBS = 30;
rBS = 0.38/2;
dBS = 0.12;
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)], 1/mBS);

p.tfBSPit = zpk([], -wBSPit*[1/(2*QBSPit) + sqrt((1/(2*QBSPit))^2 - 1), ...
                      1/(2*QBSPit) - sqrt((1/(2*QBSPit))^2 - 1)], 1/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)], 1/mPRM);

p.tfPRMPit = zpk([], -wPRMPit*[1/(2*QPRMPit) + sqrt((1/(2*QPRMPit))^2 - 1), ...
                      1/(2*QPRMPit) - sqrt((1/(2*QPRMPit))^2 - 1)], 1/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;

%% 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 = 0.1; %100mW