Pykat plots differently to Finesse for auto-alignment example
This code has different output between direct Finesse and Pykat:
%----------------------------------------------------------------------------------------------------------
% Finesse input file to compute the alignment signals generated from a
% cavity in reflection using the Ward technique
% Paul Fulda 17.02.2012
%----------------------------------------------------------------------------------------------------------
l laser 1 0 nin % Laser P=1W f_offset=0Hz
mod EOM 15M 0.001 1 pm nin n0 % Phase modulator f_mod=15MHz, modulation index=0.001
maxtem 3 % Include HG modes up to order 3
s s0 0 n0 n1
bs pickoff 0.1 0.9 0 45 n1 dump n2 n3 % Beam splitter with R=0.1, T=0.9 at zero tuning
s s1 0.1 n2 n4 % Space 10cm length
m ITM 0.99 0.01 0 n4 n5 % Cavity input mirror with R=0.99, T=0.01, at zero tuning
s scavity 1 n5 n6 % Space 1m length
m ETM 0.99 0.01 0 n6 n7 % Cavity end mirror with R=0.99, T=0.01, at zero tuning
s s2 0.1 n3 n8 % Space 10cm length
bs bsQPD 0.5 0.5 0 45 n8 n9 n10 dump % Beam splitter with R=T=0.5 at zero tuning
s sQPD1 0.1 n9 n11 % Space 10cm length
s sQPD2 0.1 n10 n12 % Space 10cm length
cav cavity ITM n5 ETM n6 % Trace cavity eigenmode for the cavity (mirrors ITM and ETM)
trace 2 % Display results of cavity trace to terminal output
attr ETM Rc 1.3 % Add curvature with radius 1.3m to mirror ETM
attr ETM xbeta 0 % Add a variable for the angular tuning of mirror ETM
attr ITM xbeta 0 % Add a variable for the angular tuning of mirror ITM
pd1 PDrefl 15M 0 n8* % Photodetector with demodulation at 15MHz, demodulation phase 0
attr sQPD1 g 40 % Fix the Gouy phase shift the space QPDsplit2QPDrefl1 to 40 degrees
attr sQPD2 g 130 % Add 90 deg Gouy phase shift to the space QPDsplit2QPDrefl2
pd1 QPDrefl1 15M 0 n11 % Photodetector with demodulation at 15MHz, demod. phase 0 deg
pdtype QPDrefl1 x-split % Specify that QPDrefl1 is a split photodiode
pd1 QPDrefl2 15M 0 n12 % Photodetector with demodulation at 15MHz, demod. phase 0 deg
pdtype QPDrefl2 x-split % Specify that QPDrefl2 is a split photodiode
set err PDrefl re % Define the signal from PDrefl to be used to generate error signal
lock z $err 3000 10n % Generate feedback signal, gain of 3000, lock accuracy of 10ppm
put ETM phi $z % Apply feedback signal to the tuning of mirror ETM
noplot z % Don't plot the feedback signal
%xaxis ITM xbeta lin 0 0.8m 500 % Sweep misalignment of mirror ITM from 0 to 0.8mrad
xaxis ETM xbeta lin 0 0.8m 500 % Sweep misalignment of mirror ETM from 0 to 0.8mrad
Finesse:
Pykat:
Looks like noplot z
is being ignored by Pykat's plot
function...