152
edits
Josh Notebook: Difference between revisions
Jump to navigation
Jump to search
no edit summary
No edit summary |
No edit summary |
||
|
'''5/16/2014'''
The stability of the 1064 laser was really good today. I think it is back to normal. I'm not sure what changed; we didn't do anything to correct it.
We set up a bunch of cardboard and fabric to shield light so that we could do a visual search for 633 (785 anti-Stokes) after the prism. Even though the light reaching the prism had already gone through a 1000nm shortpass dichroic and 2 785 notch filters, we still carefully blocked the 785, 807, and 1064 beams on the output side of the prism. The beam propagates maybe 90 cm after going through the prism.
We almost certainly saw 633! We couldn't see it on the spectrum analyzer yet, so I'm not 100% sure, but I'm about 98% sure it's real.
We were able to see a bright red beam that did all of the following
-flashed when we had only the modulation on, but no lock
-faded and came back when we turned down and back up the 1064 power
-seemed to correspond with the resonance peaks of the cavity
-seemed to correspond with the turning on and off of the modulation RF
It was a bit confusing, though, because in addition to the (probable) 633 that has the above characteristics, you can still see red light coming from the prism. This other red light is constant in intensity, in contrast to the 633. I'm not sure exactly what is from, but it must be from the 785 beam. Maybe it is diffuse scattered light from the reflections of the (small amount of) 785 that reaches the prism. At its best, the 633 was seen to be at least as bright as this other constant beam, if not brighter. The 633 seemed to be coming from the same location on the prism as this other beam, though it was visible when the prism was viewed at a slightly different angle.
We initially overlapped the transmitted 785 (through the dichroic) and the generated 807 that also is transmitted through the dichroic. We did this with the Newport camera.
We forgot to see how the beam overlap affected the light. We'll do this on Monday.
This was with 1/3 atm of D2.
David, Jared, Nick, and I all saw it. Once we found it, we easily saw it multiple times, and it seems easy to reproduce.
'''5/15/2014'''
| |||