Noise issue, posted by Ronic Chiche at ThomX igloo about lasers and optics | detectors and electronics 
|
since several days, we see that the locking is more and more unstable and the lock duration was sometime less than 20-30 seconds !
1) I tried to optimize the feedback loops
I discovered that the gain on the fast loop on the laser EOM was very low and was almost uneffective for the global stability of the lock (I |
Noise issue, posted by Ronic Chiche at ThomX igloo about lasers and optics | detectors and electronics
|
yesterday, in the same conditions, we had so many locking issues... exactly in the same way than before. :-(
so we still have "locking issues" depending on something we didn't find...
today, we removed the "1/2 voltage divider" before the PZT amplifier to get back the full dynamic. |
|
High frequency noise, posted by Ronic Chiche at ThomX igloo about lasers and optics | detectors and electronics
|
This morning, I installed a high-voltage probe (1:1000) on the AC-line to see if one could detect a correlation between lock losses and AC-line voltage
variations.
I observed many lock losses but without any variation or correlation of the AC-line signal (scope set in "peak detect" with "envelope" |
|
Laser Amplifier used at 70%, posted by Ronic Chiche at ThomX igloo about lasers and optics
|
today, I installed a laser dump just before the telescope to avoid any high power (50W instead of 17W usually) issue in the injection line.
last time, we saw some plastic mounts of the polarizers slightly burnt because of some small misalignment.
I used a thorlabs LB2 (see picture) which is able to manage 80W CW or 25J/cm2 pulses => this is OK in both cases : 50W CW / 1.5µJ/pulse |