if 1
    file='yarmRing.txt';
    ind=89:106;
    ofs=7;
    ofsm=6;
    tit='Ring-down Y-arm';
    Loss=2.8e-2;
    T=0.48e-2;
else
    file='xarmRing.txt';
    ind=2908:3100;
    ofs=15;
    ofsm=6;
    tit='Ring-down X-arm';
    Loss=4e-5;
    T=0.44e-2;
end


cal = 1;%2^14/1000; % cts/Buildup

cav.T1=T;
cav.T2=Loss;
cav.L=3000;
cav.RoC1=2000;
cav.RoC2=2000;
cav.delta=0;

cv=calculate2MirrorCavity(cav);

Finesse=cv.finesse
Prefl=cv.onRes.powerREFL

%
r1=sqrt(1-cav.T1);
r2=sqrt(1-cav.T2);
rrt=r1*r2;
TauHalf=1/(-2*log2(rrt)*cv.FSR)

data=load(file);

t=data(ind,1)-data(ind(ofs),1);
dk=mean(data(ind(end-5:end),2));
y=(data(ind,2)-17.0)/cal;
tt=t(ofsm):1e-5:t(end);
m=(data(ind(ofs),2)-dk)/cal *2.^(-tt/TauHalf);
plot(t,y,tt,m)
grid on
xlabel('sec');
ylabel('Cavity power buildup (cts)')
Fin=[': Finesse = ',num2str(Finesse),...
    ' / Tau\_half = ',num2str(TauHalf*1e3),'msec',...
    ' / P\_Refl\_Rat = ',num2str(Prefl)];
title([tit,Fin]);

dark=14.56;
locked=16.04;
unlocked=17.5;
Prefl_=(locked-dark)/(unlocked-dark)

cv.onRes.powerBuildup