Time-domain model for advanced LIGO interferometer

A time-domain model for AdvLIGO interferometer has been implemented using LIGO End to End simulation framework. AdvLIGO interferometer configuration is a dual-recycled Fabry-Perot Michelson. The system is highly complex: it requires a good understanding in the control of the microscopic positions of seven mirrors to keep five strongly-coupled interferometric degrees of freedom at their working point. The transition from the uncontrolled to the controlled state (lock acquisition) necessitates a time-domain simulation to understand and guide the lock acquisition process using fast feedback systems. A productive interplay between simulation and experiment is required to achieve a good result. AdvLIGO interferometer is not yet ready but its configuration will be tested at CalTech's 40m laboratory in the near future, as it is the closest experiment to AdvLIGO. The time-domain model is built-up using macros to define IFO parameters: in this way one is able to switch easily between the 40m configuration and the Advanced LIGO configuration.