I have measured the violin mode using the most recent lock data (February 10th ~5pm). Due to the lack of precisions in the existing information and the mismatch in values I was not able to identify any of the peak except for the ITMX BR (Back Right) at 499.9 Hz. The violin mode found in the recent lock data are as follow:
499.9, 505.58, 505.71, 505.80, 505.85, 505.92, 506.92, 507.16, 507.20, 507.36, 508.01, 508.15, 508.20, 508.85 Hz
The (fundamental harmonic) violin mode is expected to be somewhere between 500Hz and 520 Hz. Not every line is present - possibly due to high noise floor.
The violin mode has been previously identified as follow:
| ITMY (alog11184) | Frequency (Hz) | Bin Width (Hz) |
| BL | 501.5 | 0.25 |
| BR | 501.3 | 0.25 |
| FL | 504.2 | 0.25 |
| FR | 502.8 | 0.25 |
| ETMY (alog9359) | ||
| BL | 508 | 0.125 |
| BR | 508.1 | 0.125 |
| FL | 507.9 | 0.125 |
| FR | 507.6 | 0.125 |
| ITMX (alog11044) | ||
| BL | 501.2 | 0.06 |
| BR | 499.9 | 0.06 |
| FL | 502.2 | 0.06 |
| FR | 500.8 | 0.06 |
| ETMX (alog6858) | ||
| BL | 505 | ? |
| BR | 506.5 | ? |
| FL | 506.5 | ? |
| FR | 505 | ? |
Positions of the wire:
BL = Back Left
BR = Back Right
FL = Front Left
FR = Front Right
Where's left and where's right you ask? I'm trying to find the answer myself!
The designations back, front, left and right refer to looking at the reflective coating of the optic - so looking at the mirror from inside the arm. Don't forget that each mode will be split by about 0.07 Hz (based on LLO fibers) with relative amplitudes dependent on orientation of the fiber axes.