Technical issues on control scheme
Original note
Optical configuration
- homodyne phase far from 90 deg
- unbalanced SB with DRSE
These can be an issue with our own risk as aLIGO and AdVirgo will start with BRSE configuration and they do not plan to change the homodyne phase from 90 deg.
Input optics
- Mach-Zehnder noise
- AM
f1 and f2 are quite close (11.25 MHz:45 MHz = 1:4)
These are also unique for LCGT.
Control
- photodetector for double demodulation (dual resonances; if we use a single PD)
- quality of the light at OMC-REFL
- detector noise is currently not included in the loop-noise calculation (it should!)
see http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/LCGT/subgroup/ifo/ISC/Issues for other issues.