1 %
   2 %        C1lentickle1.m
   3 %
   4 %     * OLT
   5 %     * PM coupling
   6 %     * AM coupling
   7 %     * Seismic noise
   8 %                            Feb 2012 KK
   9 %
  10 %
  11 
  12 
  13 setupLentickle; 
  14 
  15 %% Run the lentickle engine
  16 
  17 % interferometer model
  18 opt = optC1(paramC1DRMI); % create the opt object
  19 opt = probesC1_00(opt, paramC1DRMI);
  20 
  21 % control model
  22 cucumber = C1cucumber(opt); % create the cucumber structure
  23                                      % look at exampleMICHcucumber.m for
  24                                      % more info about the cucumber.
  25 % frequency vector
  26 fHigh = 10000; fLow = 0.5;
  27 f = logspace(log10(fLow),log10(fHigh),500).'; % choose the frequency array we will use
  28 
  29 % get the closed loop results
  30 
  31 results = lentickleEngine(cucumber,[],f); % calculate all results
  32 
  33 %% Transfer functions
  34 % All the transfer functions (which include closed loops and all cross
  35 % coupling effects) can be extracted from the results structure, and the
  36 % pickleTF function makes that easy.
  37 
  38 %% Open Loop Gains
  39 % We will calculate the open loop gains of our two degrees of freedom, the
  40 % differential and common modes of the arms, 'DIFF' and 'COMM'. pickleTF
  41 % will easily give us the closed loop gain, and calulating the open loop
  42 % gain from that is fairly easy. (OLG = 1 - 1./CLG)
  43 
  44 MICHOLG = 1 - 1./pickleTF(results,'MICH','MICH');
  45 PRCLOLG = 1 - 1./pickleTF(results,'PRCL','PRCL');
  46 SRCLOLG = 1 - 1./pickleTF(results,'SRCL','SRCL');
  47 
  48 % make a plot of them
  49 
  50 figure(1)
  51 subplot(2,1,1)
  52 loglog(f,abs(MICHOLG),'r',f,abs(PRCLOLG),'b',f,abs(SRCLOLG),'--g','Linewidth',2);
  53 title('Open Loop Gain')
  54 ylabel('Magnitude')
  55 legend('MICH','PRCL','SRCL')
  56 xlim([fLow fHigh])
  57 grid on
  58 
  59 subplot(2,1,2)
  60 semilogx(f,180/pi*angle(MICHOLG),'r',f,180/pi*angle(PRCLOLG),'b',f,180/pi*angle(SRCLOLG),'--g','Linewidth',2);
  61 ylabel('Phase (degrees)')
  62 xlabel('Frequency (Hz)')
  63 xlim([fLow fHigh])
  64 grid on
  65 
  66 %% Noise Transfer Functions
  67 % Here we will calculate the transfer function of laser noises to our
  68 % length sensors, we will calibrate the sensor in terms of meters of the
  69 % relevant degree of freedom.
  70 
  71 
  72 
  73 %% Calibrations
  74 % First we will calculate the calibration of AS_Q in DIFF meters, and
  75 % REFL_I in COMM meters.
  76 
  77 % ASQ2 MICH
  78 ASQ2_MICH_calmeters = pickleTF(results,'IX','MICH') - pickleTF(results,'IY','MICH'); % units of [AS_Q counts]/m
  79 % REFL_3I1 PARCL
  80 REFL3I1_P_calmeters = pickleTF(results,'PR','PRCL') ;              % units of [REFL_I counts]/m
  81 % AS3Q2 SRCL
  82 AS3Q2_S_calmeters = pickleTF(results, 'SR', 'SRCL'); 
  83 
  84 
  85 
  86 %% PM noise coupling
  87 % Now we will calculate the coulping of laser frequency noise to AS_Q and
  88 % REFL_I. The PM 'mirror' is the phase modulator actuator, we divide by
  89 % i*f to get frequency.
  90 
  91 FMtoASQ2 = pickleTF(results,'PM','AS_Q2') ./ ( 1i * f ); % units of [AS_Q counts]/Hz
  92 FMtoREFL3I1 = pickleTF(results,'PM','REFL_3I1') ./ ( 1i * f ); % units of [REFL_I counts]/Hz
  93 FMtoAS3Q2 = pickleTF(results,'PM','AS_3Q2') ./ (1i *f);
  94 
  95 % Now we calibrate in terms of meters.
  96 
  97 FMtoMICH = FMtoASQ2 ./ ASQ2_MICH_calmeters; % units of m/Hz
  98 FMtoPRCL = FMtoREFL3I1 ./ REFL3I1_P_calmeters; % units of m/Hz
  99 FMtoSRCL = FMtoAS3Q2 ./ AS3Q2_S_calmeters;
 100 
 101 % plots
 102 
 103 figure(2)
 104 subplot(2,1,1)
 105 loglog(f,abs(FMtoMICH),'r',f,abs(FMtoPRCL),'b',f,abs(FMtoSRCL),'g','Linewidth',2);
 106 title('Frequency Noise Coupling')
 107 ylabel('Magnitude (m/Hz)')
 108 legend('MICH (ASQ2)','PRCL(REFL3I1)','SRCL(AS3Q2)')
 109 xlim([fLow fHigh])
 110 grid on
 111 subplot(2,1,2)
 112 semilogx(f,180/pi*angle(FMtoMICH),'r',f,180/pi*angle(FMtoPRCL),'b',f,180/pi*angle(FMtoSRCL),'g','Linewidth',2);
 113 ylabel('Phase (degrees)')
 114 xlabel('Frequency (Hz)')
 115 xlim([fLow fHigh])
 116 grid on
 117 
 118 %% AM Noise coupling
 119 %
 120 % Same manner as FM coupling
 121 %
 122 
 123 AMtoASQ2 = pickleTF(results,'AM','AS_Q2') ; % units of [AS_Q counts]/Hz
 124 AMtoREFL3I1 = pickleTF(results,'AM','REFL_3I1'); % units of [REFL_I counts]/Hz
 125 AMtoAS3Q2 = pickleTF(results,'AM','AS_3Q2');
 126 
 127 AMtoMICH = AMtoASQ2 ./ ASQ2_MICH_calmeters; % units of m/Hz
 128 AMtoPRCL = AMtoREFL3I1 ./ REFL3I1_P_calmeters; % units of m/Hz
 129 AMtoSRCL = AMtoAS3Q2 ./ AS3Q2_S_calmeters;
 130 
 131 % plots
 132 
 133 figure(3)
 134 subplot(2,1,1)
 135 loglog(f,abs(AMtoMICH),'r',f,abs(AMtoPRCL),'b',f,abs(AMtoSRCL),'g','Linewidth',2);
 136 title('Amplitude Noise Coupling')
 137 ylabel('Magnitude (/Hz)')
 138 legend('MICH (ASQ2)','PRCL(REFL3I1)','SRCL(AS3Q2)')
 139 xlim([fLow fHigh])
 140 grid on
 141 subplot(2,1,2)
 142 semilogx(f,180/pi*angle(AMtoMICH),'r',f,180/pi*angle(AMtoPRCL),'b',f,180/pi*angle(AMtoSRCL),'g','Linewidth',2);
 143 ylabel('Phase (degrees)')
 144 xlabel('Frequency (Hz)')
 145 xlim([fLow fHigh])
 146 grid on
 147 
 148 
 149 %% Sesimic noise estimation
 150 
 151 S = load('seismic_gwinc.mat');    % gwinc data, m/rtHZ, ASD
 152 Sdata0 = interp1(S.seismic.darmseis_f, S.seismic.darmseis_x, f, 'cubic', NaN);
 153 Sdata = Sdata0;
 154 
 155 % MICH (ASQ2)
 156 SdataMICH = sqrt( (Sdata.*pickleTF(results, 'IX','MICH')).^2 ...
 157                 + (Sdata.*pickleTF(results, 'IY','MICH')).^2 ...
 158             + (Sdata.*pickleTF(results, 'PR','MICH')).^2 ...
 159             + (Sdata.*pickleTF(results, 'SR','MICH')).^2 );  % m/rtHz * cts/m = cts/rtHz
 160 
 161          seis_calM = SdataMICH ./ ASQ2_MICH_calmeters;     %cts/rtHz/(cts/m)=m/rtHz 
 162 
 163 % PRCL (REFL3I1)
 164 SdataPRCL = sqrt( (Sdata.*pickleTF(results, 'IX','PRCL')).^2 ...
 165                 + (Sdata.*pickleTF(results, 'IY','PRCL')).^2 ...
 166             + (Sdata.*pickleTF(results, 'PR','PRCL')).^2 ...
 167             + (Sdata.*pickleTF(results, 'SR','PRCL')).^2 );  % m/rtHz * cts/m = cts/rtHz
 168 
 169          seis_calP = SdataPRCL ./ REFL3I1_P_calmeters;     %cts/rtHz/(cts/m)=m/rtHz 
 170 
 171 % SRCL (AS3Q2)
 172 SdataSRCL = sqrt( (Sdata.*pickleTF(results, 'IX','SRCL')).^2 ...
 173                 + (Sdata.*pickleTF(results, 'IY','SRCL')).^2 ...
 174             + (Sdata.*pickleTF(results, 'PR','SRCL')).^2 ...
 175             + (Sdata.*pickleTF(results, 'SR','SRCL')).^2 );  % m/rtHz * cts/m = cts/rtHz
 176 
 177          seis_calS = SdataSRCL ./ AS3Q2_S_calmeters;     %cts/rtHz/(cts/m)=m/rtHz 
 178 
 179          
 180 
 181 % plot
 182 figure(4)
 183 loglog(f,sqrt(4*abs(Sdata).^2),'k','Linewidth',2)
 184 hold on
 185 loglog(f,abs(seis_calM),'b',f,abs(seis_calP),'g--',f,abs(seis_calS),'m--','Linewidth',2)grid on
 186 title('Seismic noise level estimate')
 187 ylabel('ASD [m/rtHz]')
 188 xlabel('Frequency (Hz)')
 189 legend('raw data added for 4 optics','MICH calibrated','PRCL calibrated','SRCL calibrated')
 190 xlim([fLow fHigh])
 191 
 192 
 193 %% Thermal noise budget