def katFP(par):
"""Make a Finesse Fabry Perot cavity
Inputs:
par: parameter dictionary
Returns:
kat: the model
"""
fmod = par['Mod']['fmod']
gmod = par['Mod']['gmod']
kat = pykat.finesse.kat()
kat.lambda0 = par['lambda0'] # set the laser wavelength
# Make the cavity
# In this case it's very simple, but in more complicated models you can
# easily loop through all of the optics if you've defined the parameters
# in a dictionary
mirrors = ['EX', 'IX']
for mirror in mirrors:
# add the mirror and set the optic properties
fin.addMirror(kat, mirror, **par[mirror]['opt'])
# set the mechanical response
pmech = par[mirror]['mech']
poles = np.array(
resRoots(2 * np.pi * pmech['f0'], pmech['Q'], Hz=False))
fin.setMechTF(kat, mirror, [], poles, 1 / pmech['mass'])
fin.addSpace(kat, 'IX_fr', 'EX_fr', par['Lcav'])
fin.setCavityBasis(kat, 'IX_fr', 'EX_fr')
# add input
fin.addLaser(kat, 'Laser', par['Pin'])
fin.addModulator(kat, 'Mod', fmod, gmod, 1, 'pm')
fin.addSpace(kat, 'Laser_out', 'Mod_in', 0)
fin.addSpace(kat, 'Mod_out', 'IX_bk', 0)
# add DC and RF photodiodes
fin.addReadout(kat, 'REFL', 'IX_bk', fmod, 0)
return kat
def katFP():
kat = pykat.finesse.kat()
fin.addMirror(kat, 'EX', Thr=0)
fin.addMirror(kat, 'IX', Thr=Ti)
fin.addSpace(kat, 'IX_fr', 'EX_fr', Lcav)
for optic in ['EX', 'IX']:
fin.setMechTF(kat, optic, [], [0, 0], 1)
fin.addLaser(kat, 'Laser', Pin)
fin.addModulator(kat, 'Mod', fmod, gmod, 5, 'pm')
fin.addSpace(kat, 'Laser_out', 'Mod_in', 0)
fin.addSpace(kat, 'Mod_out', 'IX_bk', 0)
fin.addReadout(kat, 'REFL', 'IX_bk', fmod, 0)
fin.monitorAllQuantumNoise(kat)
fin.monitorMotion(kat, 'EX')
kat.phase = 2
return kat
def homodyne_po(kat, phi):
fin.addHomodyneReadout(kat, 'AS', qe=0.9, LOpower=0)
fin.addSpace(kat, 'AS_PO_frR', 'AS_BS_frI', 0)
fin.addSpace(kat, 'LO_PO_frR', 'AS_LOphase_frI', 0)
kat.AS_LOphase.phi = phi / 2
fin.monitorAllQuantumNoise(kat)
def homodyne_lo(kat, phi):
fin.addHomodyneReadout(kat, 'AS', phi, qe=0.9)
fin.addSpace(kat, 'AS_PO_frR', 'AS_BS_frI', 0)
fin.monitorAllQuantumNoise(kat)
def katFPMI(sqAng, sqdB, rf=True):
kat = pykat.finesse.kat()
fin.addMirror(kat, 'EX')
fin.addMirror(kat, 'EY')
fin.addMirror(kat, 'IX', Thr=Ti)
fin.addMirror(kat, 'IY', Thr=Ti)
fin.addBeamSplitter(kat, 'BS')
kat.BS.phi = np.sqrt(2) * 45
Tpo = 1 - 1 / Pin
fin.addBeamSplitter(kat, 'LO_PO', Thr=Tpo, aoi=45, comp=True)
for optic in ['EX', 'EY', 'IX', 'IY']:
fin.setMechTF(kat, optic, [], poles, 1 / M)
fin.addLaser(kat, 'Laser', Pin)
if rf:
fin.addModulator(kat, 'Mod', fmod, gmod, 1, 'pm')
fin.addSpace(kat, 'Laser_out', 'Mod_in', 0)
fin.addSpace(kat, 'Mod_out', 'LO_PO_frI', 0)
else:
fin.addSpace(kat, 'Laser_out', 'LO_PO_frI', 0)
fin.addSpace(kat, 'LO_PO_bkT', 'BS_frI', 0)
fin.addSpace(kat, 'BS_bkT', 'IX_bk', lx)
fin.addSpace(kat, 'IX_fr', 'EX_fr', Larm)
fin.addSpace(kat, 'BS_frR', 'IY_bk', ly)
fin.addSpace(kat, 'IY_fr', 'EY_fr', Larm)
fin.addFaradayIsolator(kat, 'FI')
fin.addSpace(kat, 'BS_bkO', 'FI_fr_in', 0)
fin.addBeamSplitter(kat, 'AS_PO', aoi=45, Thr=0.5)
fin.addSpace(kat, 'FI_fr_out', 'AS_PO_frI', 0)
if rf:
fin.addReadout(kat, 'AS', 'AS_PO_bkT', fmod, 0)
fin.addSqueezer(kat, 'Sqz', sqAng, sqdB)
fin.addSpace(kat, 'Sqz_out', 'FI_bk_in', 0)
return kat
def katFPMI(par):
"""Make a Finesse Fabry FPMI
Inputs:
par: parameter dictionary
Returns:
kat: the model
"""
fmod = par['Mod']['fmod']
gmod = par['Mod']['gmod']
kat = pykat.finesse.kat()
kat.lambda0 = par['lambda0'] # set the laser wavelength
# Add optics and set mechanical plants
mirrors = ['EX', 'IX', 'EY', 'IY']
splitters = ['BS']
for mirror in mirrors:
fin.addMirror(kat, mirror, **par[mirror]['opt'])
for splitter in splitters:
fin.addBeamSplitter(kat, splitter, **par[splitter]['opt'])
for optic in mirrors + splitters:
pmech = par[optic]['mech']
fin.setMechTF(kat, optic, pmech['zs'], pmech['ps'], pmech['k'])
# need to microscopically tune the BS to make the AS port dark due to
# the Finesse convention that transmission gets a 90 deg phase shift
# Setting, for example, kat.EX.phi = 90, kat.IX.phi = 90, and kat.BS.phi = 0
# would also work
kat.BS.phi = np.sqrt(2) * 45
# Add input
fin.addLaser(kat, 'Laser', par['Pin'])
fin.addModulator(kat, 'Mod', fmod, gmod, 1, 'pm')
fin.addSpace(kat, 'Laser_out', 'Mod_in', 0)
# Add Faraday isolator
fin.addFaradayIsolator(kat, 'FI')
fin.addSpace(kat, 'Mod_out', 'FI_fr_in', 0)
fin.addSpace(kat, 'FI_fr_out', 'BS_frI', 1)
# Add links
plen = par['Length']
# X arm
fin.addSpace(kat, 'BS_bkT', 'IX_bk', plen['lx'])
fin.addSpace(kat, 'IX_fr', 'EX_fr', plen['Lx'])
# Y arm
fin.addSpace(kat, 'BS_frR', 'IY_bk', plen['ly'])
fin.addSpace(kat, 'IY_fr', 'EY_fr', plen['Ly'])
# Add output probes
fin.addSpace(kat, 'FI_bk_out', 'REFL_in', 1, new_comp='REFL')
fin.addSpace(kat, 'BS_bkO', 'AS_in', 1, new_comp='AS')
# demod phases chosen to maximize CARM in REFL_I and DARM in AS_Q
fin.addReadout(kat, 'REFL', 'REFL_in', fmod, 125)
fin.addReadout(kat, 'AS', 'AS_in', fmod, 11)
# add probes to monitor the motion of the test masses and beamsplitter
fin.monitorMotion(kat, 'EX')
fin.monitorMotion(kat, 'EY')
fin.monitorMotion(kat, 'BS')
# add probes to compute the shotnoise of all probes in the model
fin.monitorAllQuantumNoise(kat)
return kat
gi = 1 - Lcav / Ri ge = 1 - Lcav / Re r = 2 / ((gi - ge) + np.sqrt((gi - ge)**2 + 4)) I = 25 f0 = 1 Q = 100 poles = np.array(ctrl.resRoots(2 * np.pi * f0, Q, Hz=False)) kat = pykat.finesse.kat() # make the cavity fin.addMirror(kat, 'EX', Chr=1 / Re) fin.addMirror(kat, 'IX', Thr=Ti, Chr=1 / Ri) fin.addSpace(kat, 'IX_fr', 'EX_fr', Lcav) fin.setCavityBasis(kat, 'IX_fr', 'EX_fr') # set the pitch response fin.setMechTF(kat, 'EX', [], poles, 1 / I, doftype='pitch') fin.setMechTF(kat, 'IX', [], poles, 1 / I, doftype='pitch') # add input fin.addLaser(kat, 'Laser', Pin) fin.addModulator(kat, 'Mod', fmod, gmod, 1, 'pm') fin.addSpace(kat, 'Laser_out', 'Mod_in', 0) fin.addSpace(kat, 'Mod_out', 'IX_bk', 0) # add DC and RF photodiodes fin.addReadout(kat, 'REFL', 'IX_bk', fmod, 0, doftype='pitch')
def katMI(dpx, dpb, aoib):
kat = pykat.finesse.kat()
fin.addMirror(kat, 'EX', Thr=0, phi=dpx, Chr=1 / Re)
fin.addMirror(kat, 'EY', Thr=0, Chr=1 / Re)
fin.addMirror(kat, 'IX', Thr=Ti, phi=dpx, Chr=1 / Ri)
fin.addMirror(kat, 'IY', Thr=Ti, Chr=1 / Ri)
fin.addBeamSplitter(kat, 'BS', aoi=aoib, phi=dpb)
fin.addLaser(kat, 'Laser', Pin)
fin.addModulator(kat, 'Mod', fmod, gmod, 5, 'pm')
fin.addSpace(kat, 'Laser_out', 'Mod_in', 0)
fin.addSpace(kat, 'Mod_out', 'BS_frI', 1)
fin.addSpace(kat, 'BS_bkT', 'IX_bk', lx)
fin.addSpace(kat, 'IX_fr', 'EX_fr', Lcav)
fin.setCavityBasis(kat, 'IX_fr', 'EX_fr')
fin.addSpace(kat, 'BS_frR', 'IY_bk', ly)
fin.addSpace(kat, 'IY_fr', 'EY_fr', Lcav)
fin.setCavityBasis(kat, 'IY_fr', 'EY_fr')
fin.addSpace(kat, 'BS_bkO', 'AS_in', 1, new_comp='AS')
kat.phase = 2
return kat