LIGO Document E1200166-x0
- Document tree for the interferometer sensing and control system, transmission monitor in EX and EY. The transmission monitor senses the beam transmitted by the ETM using two QPDs (near- and far-field). These QPD signals are used for global arm cavity alignment control. The transmission monitor also includes an optical path for the green ALS beam to inject it into the arm cavity, including 2 QPDs for pointing control of the green beam.
For the optical layout and optics specifications see:
DCC Version 3.4.1, contact