%--------------- o p t A L I G O . m -----------------
% Creates an Optickle model instance of Advanced LIGO
%
% by Matt Evans (2012 March)
%
%--------------------------------------------------------
%
% [Description]
% This function creates an interferomter based on the information
% specified in 'par' structure variable.
% The function adds necessary components such as laser, EOM, mirrors in
% to the model and then links all those components while spcifying the
% distance between the components
%
% Example usage:
%              par = paramALIGO(10);  % argument is input power
%              opt = optALIGO(par);
%              opt = probesALIGO(opt, par);
%
%--------------------------------------------------------
% 
% [Notes]
% In the current setting PR3, SR2 and SR3 are omitted for simplicity.
% However PR2 is included as a high reflective beam splitter so that
% the POP2 (light coming from BS to PRM) signal can be obtained.
% 
%--------------------------------------------------------
%

function opt = optALIGO(par)

  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % Add a Field Source
  
  % create an empty model, with frequencies specified
  opt = Optickle(par.Laser.vFrf);
  
  % add a source, with RF amplitudes specified
  opt.addSource('Laser', par.Laser.vArf);
  
  % add modulators for Laser amplitude and phase noise
  opt.addModulator('AM', 1);
  opt.addModulator('PM', 1i);
  
  % link, output of Laser is PM->out
  opt.addLink('Laser', 'out', 'AM', 'in', 0);
  opt.addLink('AM', 'out', 'PM', 'in', 0);
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % Add Input Optics  
  
  % Modulators
  opt.addRFmodulator('Mod1', par.Mod.f1, 1i * par.Mod.g1);
  opt.addRFmodulator('Mod2', par.Mod.f2, 1i * par.Mod.g2);
  
  % link, No MZ
  opt.addLink('PM', 'out', 'Mod1', 'in', 5);
  opt.addLink('Mod1', 'out', 'Mod2', 'in',0);
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % Add Core Optics
  %
  % The parameter struct must contain parameters the following
  % for each mirror: T, L, Rar, mechTF, pos, RoC, AoI
  
  listMirror = {'PR','SR', 'BS', 'IX', 'IY', ...
    'EX', 'EY', 'PR2', 'OMCa', 'OMCb'};
  
  for n = 1:length(listMirror)
    name = listMirror{n};
    p = par.(name);
    
    % add mirror or beam-splitter
    if strcmp(name, 'BS') || strcmp('PR2', name)
      opt.addBeamSplitter(name, p.AoI, 1 / p.RoC, p.T, p.L, p.Rar, 0);
    else
      opt.addMirror(name, p.AoI, 1 / p.RoC, p.T, p.L, p.Rar, 0);
    end
    
    % set mechanical transfer-functions and mirror position offsets
    opt.setPosOffset(name, p.pos);
    
    if ~isempty(p.mechTF)
      opt.setMechTF(name, p.mechTF);
      opt.setMechTF(name, p.mechTF,2); % add the same TF for pitch for testing
    end
  end
  
  % add AS port pick-off
  opt.addMirror('PO_AS', 0, 0, par.Tomc, 0, 0, 0);
  
  %%%%%%%%%%%%%%%%%%%%
  % link Modulators output to PR back input (no input Mode Cleaner)
  opt.addLink('Mod2', 'out', 'PR', 'bk', 0.2);%35);
  
  % link PR front output -> PR2 A-side fron input
  opt.addLink('PR', 'fr', 'PR2', 'frA', par.Length.PR_PR2);
  
  % link BS A-side inputs to PR2 A-side and SR front outputs
  opt.addLink('PR2', 'frA', 'BS', 'frA', par.Length.PR2_BS);
  opt.addLink('SR', 'fr', 'BS', 'bkA', par.Length.SR);
  
  % link BS A-side outputs to and IX and IY back inputs
  opt.addLink('BS', 'frA', 'IY', 'bk', par.Length.IY);
  opt.addLink('BS', 'bkA', 'IX', 'bk', par.Length.IX);
  
  % link BS B-side inputs to and IX and IY back outputs
  opt.addLink('IY', 'bk', 'BS', 'frB', par.Length.IY);
  opt.addLink('IX', 'bk', 'BS', 'bkB', par.Length.IX);
  
  % link BS B-side outputs to PR2 B-side and SR front inputs
  opt.addLink('BS', 'frB', 'PR2', 'frB', par.Length.PR2_BS);
  opt.addLink('BS', 'bkB', 'SR', 'fr', par.Length.SR);
  
  % link PR2 B-side front output to PR fron input
  opt.addLink('PR2', 'frB', 'PR', 'fr', par.Length.PR_PR2);
  
  % link the X arm
  opt.addLink('IX', 'fr', 'EX', 'fr', par.Length.EX);
  opt.addLink('EX', 'fr', 'IX', 'fr', par.Length.EX);
  
  % link the Y arm
  opt.addLink('IY', 'fr', 'EY', 'fr', par.Length.EY);
  opt.addLink('EY', 'fr', 'IY', 'fr', par.Length.EY);
  
  % tell Optickle to use this cavity basis
  opt.setCavityBasis('IX', 'EX');
  opt.setCavityBasis('IY', 'EY');
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % Link OMC
  opt.addLink('SR', 'bk', 'PO_AS', 'fr', 10);
  opt.addLink('PO_AS', 'bk', 'OMCa', 'bk', 4);
  opt.addLink('OMCa', 'fr', 'OMCb', 'fr', 1.2);
  opt.addLink('OMCb', 'fr', 'OMCa', 'fr', 1.2);
  
  opt.setCavityBasis('OMCa', 'OMCb');

end