[Shimasue, Michimura]

We are preparing a setup for BS transmission and reflectivity measurements around IMC REFL area.

Background:
 BS is designed and measured to have 50:50 transmission and reflectivity for s-polarization (Ts=49.96%, JGW-T1503347).
 But the BS transmission and reflectivity for p-polarization are unknown (Designed to have Tp=80% or so, AR for p-pol a few %, JGW-T1503347).
 To understand what is going on in the IFO for p-pol, we are planning to measure them with an another laser source during this vent.

What we did:
 - Assembled a tripod setup with a bread board to install laser source (Attachment #1)
 - Assembled a laser injection bench on the bread board (Attachment #2, now resting on IMC REFL table)
 - Assembled a tripod setup with a bar to hold a power meter to measure the incident power to the BS and BS reflected/transmistted powerr (Attachment #3)
 - We are planning to stick this power meter to ICF203 flanges between BS and ITMX or ITMY (Attachment #4 and #5)