149
edits
Zjs log: Difference between revisions
Jump to navigation
Jump to search
no edit summary
No edit summary |
No edit summary |
||
|
--[[User:Zjsimmons|Zjsimmons]] ([[User talk:Zjsimmons|talk]]) 18:25, 8 May 2014 (CDT)
* examined Josh's lockbox. It seems to short the positive rail momentarily when first connected to power and then recover. Very strange behavior. Occurs w/ ICs removed as well, so it doesn't seem to be the chips. Checked voltage ref pots, doesn't seem to be for example shorted diodes. curious.
* Having trouble tuning up the SHG cavity, could not get very nice clean modes, always some garbage in between peaks. Subsequently spun the fiber launch and totally misaligned the whole shebang. I guess it will be good practice tuning it up.
--[[User:Zjsimmons|Zjsimmons]] ([[User talk:Zjsimmons|talk]]) 17:30, 7 May 2014 (CDT)
* re: mysterious polarization noise, could it be we are blocking the beam with our fingers/fiber and that's why the power goes to zero?
* Nick showed me how to tune up the SHG cavity today. It didn't seem too bad to mess with; it'll be good to not be afraid to adjust it.
--[[User:Zjsimmons|Zjsimmons]] ([[User talk:Zjsimmons|talk]]) 23:23, 6 May 2014 (CDT)
* Figured out that the flat polished fibers were the cause of power fluctuations after the TA in 1055nm set-up. Using an angle polished fiber fixed the issue.
* Power fluctuations are also not the reason the circuit is not locking the SHG cavity. Perhaps the gain roll-off needs to be at lower freq? as we are seeing some wiggles around 420Hz (piezo resonance freq). Maybe this is involved in failure to lock. We could also try adding fast feedback branch and see what happens.
4-6-2014
| |||