NSF : Nov. 10, LIGO End to End simulation overview  Time domain simulation written in C++  Like MATLAB with Interferometer toolbox  Major physics components and tools relevant for LIGO »fields & optics, mechanics, digital and analog electronics, measured noise, state space model using ABCD matrix, etc  Flexible to apply for wide varieties of systems »from a simple pendulum to full LIGO I to adv.LIGO »from fast prototyping of subsystems to entire interferometer simulation  Easy development and maintenance »use of graphical front end for e2e programming »object orient design for easy addition of new physics

NSF : Nov. 10, Programming e2e

NSF : Nov. 10, LIGO I : Lock acquisition real and simulated observable Not experimentally observable

NSF : Nov. 10, LIGO I : Sensitivity curve

NSF : Nov. 10, m : Lock Acquisition, step 4  CARM moved to RF signal »Not yet done at 40m »REFL port HF demod (a.k.a., SP166) »Normalized by arm power »Offset and gain matched at hand over »Offset swept to zero slowly »Coupled-Cavity pole compensation required –Pole (actually more complicated) moves down as resonance is approached –Compensation filter uses sum to make a “moving zero” –More detail may be required for 40m

NSF : Nov. 10, m : Optical Spring

NSF : Nov. 10, Summary  Modular software toolboxes »mirror, laser, etc  Infrastructure tested in LIGO I »lock acquisition, sensitivity  Adv.LIGO needs dual recycled Michelson cavity »test new optics configuration »dynamics which may affect lock acquisition, like optical spring  Compare with 40m signals and controls  Design the interferometer sensing and control system using the simulation of 4000m interferometer