daniel.sigg@LIGO.ORG - posted 18:30, Thursday 06 February 2014 (9902)
Second order HOM locking
This morning the X-arm accidentally locked to what looked like a second order higher order mode of the ALS beam. The power of the transmitted light in arbitrary units was
| Zero level | 35 | 0 |
| TEM00 | 845 | 810 |
| 2nd order HOM | 150 | 115 |
This would mean about ~15% of the incident power is not mode matched to the cavity.