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Wed Feb 24 00:27:14 2010, Dmass, Lab Infrastructure, Doubling, Doubling Crystal Damaged
Thu Feb 25 01:00:31 2010, Dmass, Lab Infrastructure, Doubling, Doubling Experiment Update!
Fri Feb 26 01:50:06 2010, Dmass, Lab Infrastructure, Doubling, Doubling Experiment Update!
Fri Feb 26 16:19:05 2010, Dmass, Lab Infrastructure, Doubling, Doubling Experiment Update!
Thu Feb 25 01:00:31 2010
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Doubling Experiment Update!
Update on rebuilding:
Rana found me a 4 mirror REO package with 2 mirrors in it.
One of these is a supermirror.
The other is something unknown that looks different, has an engraved barrel, and is most definitely NOT high reflective (maybe a splitter) at 1064.
I can't find the 1064 transmission (of 100 mW) of the supermirror on a viewer, or sensitive card. It appears to be very small. This is good.
I see bright 532 spots reflected from both surfaces of this mirror. This is less than good.
I still have 100 uW transmitted, which is within a factor a 3 of my max power. This will give me around 1V DC with a 50K load resistor on one of the PDs I will use (below).
I am using some 90% R 45P (the beam is S) to dump a large fraction of my IR power before my PDs.
I took one of the ISS PDs off the 40m PSL table. Siobhan was her name.
I had another ISS PD from Stefan's time here.
I pulled the 500 ohm SM transimpedance resistor from both of these, and replaced it with a 500 Ohm thin film resistor from the 40m. (I didn't get a good pic, but had no problems soldering, and Koji gave me a tired thumbs up when I asked him if I "did it wrong")
I am going to use the ISS PD box to power and readout these.
I also have two DET110's and two nice and old Thorlabs PDs of unknown model number (but known PD type: Hamamatsu S1223).
The DET110's have a quoted NEP of 2e-14 W/rtHz and the Hamamatsu's have a quoted NEP of 1e-14.
These numbers are way better than the newer thorlabs PDs I was using (which were total shite - like 10 pA/rtHz NEPs of 1e-11 to 1e-12. Terrible.)
I will think about the loading tomorrow, and see what I can get away with for each of these. The batteries are 12 and 22.5V, respectively.
A 150K load would fill the DAQ with what I have, so maybe this is a good number to shoot for?
I think I have everything fitting!
Frank found some of the Si slabs we are using for the low scatter beam dumps, I am planning on fashioning two crude dumps from these (I have only 3 slabs).
I have up to 200 mW coming out of my MZ, so I have to dump some so as not to cook the ISS PDs.