Transmission Monitor System (TMS)

Related subgroups: IOO, MIF, VAC, CRY, VIS...

Also called "beam reducing telescope (BRT)" in LCGT.

Contents

Scope

Transmission monitors for IR/Green beams.

Collect 1064nm and 532nm light transmitting ETMs.
Monitor the off-centering and pitch/yaw fluctuations of the ITMs/ETMs relative to the preselected optical path.
Monitor the shape of the beam modes that transmit the arm cavity.

For each TMS,

2QPDs for 1064nm are required to monitor off-centering of the beam; one is for high gain, the other is for low gain.
2QPDs for 1064nm are required to monitor pitch/yaw misalignments of the beam; one is for high gain, the other is for low gain.
2QPDs for 532nm are required.
Remote stirring mirrors for QPDs are required at least in the initial commissioning phase.
Remote actuators for TMS chassis would be required.
CCD monitors for monitoring the beam mode transmitting the ETM are required.
Optical levers (or equivalent local monitors) are required.
Suspension system will require more signal channels?
Shutters for high gain QPDs are required.

TBD