Bots, Bureaucrats, Interface administrators, Suppressors, Administrators, Upload Wizard campaign editors
573
edits
David Notebook: Difference between revisions
Jump to navigation
Jump to search
→Daily Log
|
==Daily Log==
'''9/11/14'''
Jared and Zach noted at group meeting today that they get pretty different readings using the visible power meter head for 1064 then when they use the IR one or the thermal one (which agree well with one another). Additionally it gives significantly different readings when set ~1064 vs ~1050, which suggests it's not well calibrated near the end of the it's range. I used the visible power meter head I used to measure the 1064 beam power for the recent 633 data, so I should check and see just how much the power measurements differ compared to the other power meters. Hopefully it's a constant offset or fixed percent and we can adjust the data accordingly. Deniz did a preliminary analysis and made a theory curve. It's about a factor of 2.5 higher than the experimental data. There are still a few effects to account for that might lower the theory, and accounting for the 1064 power measurement issue will undoubtedly affect things too.
Here is the [https://wiki.physics.wisc.edu/yavuz/images/c/c7/Mixing_efficiency_analysis.png tentative graph] though.
'''9/9/14'''
Still trying to get the 1555 to lock using the vescent box. It's very hard to keep the diode single mode--are these diodes just very sensitive, or is it not feeding back properly? Talk to Deniz. I'm reading a lot about locking--Josh's thesis is helpful, as is the original PDH paper. I noticed that on the the reflected 1555 signal is saturating the photodiode. I adjusted the ND filter closest to the photodiode from 1.0 to 1.5. This signal strength is adjustable with the waveplate/beam cube right before the photodiode, but it seemed like it was dumping a lot of power into the little fluorescent stone thing and I smelled burning (I might have imagined that though).
| |||