keita.kawabe@LIGO.ORG - posted 12:37, Tuesday 18 October 2016 (30622)
H1 BRDF quite similar to L1
Hiro asked me about LHO BRDF measurements like LLO (https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=28662).
Using numbers measured by Vinny (https://dcc.ligo.org/T1600085) when the arm power was about 100kW back in January, the corresponding BRDF numbers are:
| Power on OPLEV | Distance | BRDF | |
| ITMX | 2.4uW | 33m | 2.6E-4/sr |
| ITMY | 3.9uW | 33m | 4.2e-4/sr |
| ETMX | 11.8uW | 5.6m | 3.7e-5/sr |
| ETMY | 8.9uW | 5.6m | 2.8e-5/sr |
There's no evidence that this changes with power: alog 28449