[Sheila Jenne TVo Georgia]

While trying to lock ALS we found that x-end aux laser was glitchy. An example of the sort of behavior we saw is shown in the first screenshot and indicated by the pink arrow, where noise was seen in the green and IR intensity. We thought this was due to the aux laser mode-hopping, so Sheila and I went to the end station to adjust the diode current and crystal temperature. Initially the diode current was 1.949 A and the crystal temperature was 23.73 C, we adjusted this to 1.902 A and 23.78 C.

After the initial adjustment to the laser current and temperature the green and IR power out of the laser was drifting with the crystal temperature (shown in second screenshot), also possibly due to mode-hopping. We returned to the end station to adjust the laser parameters again. The aux laser diode current is now 1.997 A and the crystal temperature ~23.67 C.

Later we determined the glitching was possibly due to the aux laser noise eater ringing, and is fixed by resetting the noise eater. In the future it would be good to have a way to monitor if the noise eater is ringing and toggle it on and off. This used to be achieved using the demod RF mon, but this was not working today.