User:Steven J. Koch/Notebook/Kochlab/2009/07/10/Power spectrum

Steve Koch 13:16, 10 July 2009 (EDT): Andy hooked up the power stabilizer. Pretty sweet actually, we're able to dial in about 85% beam power and it locks on. at 10.15 amps, and 85%, we're at about 375 mW. Something definitely was misaligned, probably a combination of the power stabilizer and the first mirror. Will be quite some time to fix it, so Andy first rotated the power stabilizer by hand while looking at the beam diffraction pattern on the video to roughly get it a little better.


 * Andy Maloney 00:08, 11 July 2009 (EDT): Ha! Sometime = 1 hour for realignment. These tweezers are my bitch.

We trapped a bead and took a power spectrum. Module isn't quite working yet. Fit does not succeed. Power spectrum is way noisy in the low freqs. Fit fails. By eye:


 * 375 mW, corner frequency is between 1 and 2 K
 * 185 mW, corner frequency is definitely less than 2K, probably less than 1K.

corner frequency of 1500 K is 0.045 pN / nm. This is too low, but I'm not confident of numbers yet.

Steve Koch 13:22, 10 July 2009 (EDT): fixed a bug (at least partially) by stopping and starting the DAQ task in the "pause" loop. Now, I am going to add in the PhreshPhotonics math.